Re: [PSES] NEMA 5-20P with IEC 60320 C13

[Richard Nute]

My understanding:

Receptacles are not de-rated.  

A single load cannot exceed 80% (or some such percentage) of the branch circuit 
loading to allow other loads on the same branch circuit.   If a single 
receptacle on the branch circuit, then the (single) load can be 100% of the 
branch circuit rating.

In the USA, a 15-amp receptacle can be used on a 20-amp branch circuit.  Since 
we don't know if the branch circuit is 15- or 20-amps, we assume the load is 
always connected to a 15-amp branch circuit with multiple receptacles.  

Rich


-Original Message-
From: Ralph McDiarmid [mailto:ralph.mcdiar...@schneider-electric.com] 
Sent: Tuesday, October 10, 2017 2:56 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] NEMA 5-20P with IEC 60320 C13

There may be a “disconnect” between SDO (standards development) and code 
writing panels at the NFPA.  For example, the 125% rule in 
Article 690 is there because the NFPA thinks that the standard test conditions 
for solar panels aren’t realistic.  They think 1,000W/sq-m irradiance is too 
low, and short circuit PV currents need a 1.25 multiplier.   

Ralph McDiarmid
Product Compliance
Engineering
Solar Business
Schneider Electric


From: Ted Eckert [mailto:07cf6ebeab9d-dmarc-requ...@ieee.org]
Sent: Tuesday, October 10, 2017 1:58 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] NEMA 5-20P with IEC 60320 C13

The various clauses of NFPA 70 are reviewed, challenged, debated, argued and 
rewritten. I don’t think the clause in question remains because nobody has 
challenged it. Part of the issue is that the electrical infrastructure in the 
U.S. has been developed around this rule. If affects circuit breaker trip 
curves, conduit fill, wire sizes and rating and many other aspects of a 
building’s electrical system. If the rule were changed, would there be problems 
switching over? Would you have overheating in older structures where circuit 
breakers were replaced without updating wiring? Wold there be other effects of 
mixing 80% and 100% rated components? How many U.S. national standards would 
need to be updated? 

It is a poor analogy, but think about switching sides that you drive on the 
road. Sweden switched on September 3, 1967. Street signs, traffic signals and 
road markings all had to be changed. Headlights had to be adjusted or re-aimed. 
For quite a while, there was a mix of left-hand and right-hand drive cars. It 
was a massive undertaking for a country with fewer people than either London or 
New York City. 

Changing the way branch circuits are rated in the U.S. could be done, but it 
would be an extremely complicated undertaking. The risks of a mismatch of 
circuits, circuit protection and loads would be significant for a long time. I 
suspect that by the time the technology evolved to the point where the 
requirement could be eliminated, it was too late and eliminating it would 
result in too much expense and rework.

Ted Eckert
Microsoft Corporation

The opinions expressed are my own and do not necessarily reflect those of my 
employer. 

From: John Woodgate [mailto:j...@woodjohn.uk]
Sent: Tuesday, October 10, 2017 12:49 PM
To: mailto:EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] NEMA 5-20P with IEC 60320 C13

Well, yes, because the IEC tends to believe that rated values are realistic and 
do not need to be adjusted downwards. I suspect that at some point in the 
distant past (maybe even nearly 100 years ago), some connectors in wide use 
were found to overheat at rated current, so the 'derating rule' was brought in, 
and no-one has challenged it since.
John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates 
https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.woodjohn.uk&data=02%7C01%7Cted.eckert%40microsoft.com%7Cb9a5abba70d24e2f093e08d51018031b%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C636432617679408094&sdata=jNpj%2FFhCHx9ir37o7Xf5GxovOe2h0nU9FIZnbo5mItE%3D&reserved=0
Rayleigh, Essex UK
On 2017-10-10 20:12, Ralph McDiarmid wrote:
The NEC (NFPA 70) talks about “continuous currents” and when to apply the 
all-too-familiar 125% rule.  Canadian Electric Code (CSA part I) has same 
requirement.  The IEC seems to have avoided it.

Ralph McDiarmid
Product Compliance
Engineering
Solar Business
Schneider Electric
D  604-422-2622

From: Kunde, Brian [mailto:brian_ku...@lecotc.com]
Sent: Monday, October 09, 2017 8:31 AM
To: mailto:EMC-PSTC@LISTSERV.IEEE.ORG
Subject: [PSES] NEMA 5-20P with IEC 60320 C13

It is my understanding that according to the US National Electric Code, 15 amp 
receptacle are derated to 12 amps max., and 20 amp receptacles are derated to 
16 amps. 

IEC 60320 C13 connectors are rated 15 amps in North America. Do I derate them 
as well or can I draw 15 amps continuous from the C13 connector?

So here is the big question:

If I have a power cord with a NEMA-5-20P at one end, IEC 60320 C13 at the other 
end, and 14awg cordage (rated 18A), can I use/ship this power cord with a 
product rated 15

Re: [PSES] IEC 61000-3-2 Confusion

[John Woodgate]

That isn't a 'condition'. The conditions are the items in the a-b-c list 
in 6.1.


John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates www.woodjohn.uk
Rayleigh, Essex UK

On 2017-10-11 21:42, James Pawson (U3C) wrote:
It was the symmetrical control for the powering of heating elements 
part that was the previous condition that was fulfilled.


Hope this helps
James

 John Woodgate wrote 

OK, I've sent a digest to the committee chair. Meanwhile, I noticed 
something that I don't quite understand:


You say that "Clause 6.1 also says that symmetrical control for 
professional equipment is OK provided one of the “above conditions” is 
fulfilled (which it is, see previous bullet)"


Which is the 'above condition' that the welder meets?

John Woodgate OOO-Own Opinions Only
J M Woodgate and Associateswww.woodjohn.uk
Rayleigh, Essex UK
On 2017-10-11 17:08, James Pawson (U3C) wrote:


Hello John,

It uses phase angle control hence the concern about the harmonics 
generated.


Manufacturer specs are single phase, 230V nominal, 3kW.

Typically used at less than a 15% duty cycle, often less, in an 
industrial environment or powered from a generator.


My *feeling* is that should be classified as professional equipment 
and exempted under Clause 7 but the IEV has 0 search for feelings.


Thanks for your help

James

*From:*John Woodgate [mailto:j...@woodjohn.uk]
*Sent:* 11 October 2017 16:49
*To:* EMC-PSTC@LISTSERV.IEEE.ORG
*Subject:* Re: [PSES] IEC 61000-3-2 Confusion

I agree that there appears to be a need for clarification, and I will 
take that up with the committee responsible. But for your particular 
case, what is critical is the nature of the 'triac control'. Is it 
phase-angle control, or 'burst firing' or something else?


John Woodgate OOO-Own Opinions Only
J M Woodgate and Associateswww.woodjohn.uk 
Rayleigh, Essex UK

On 2017-10-11 15:01, James Pawson (U3C) wrote:

Hi folks,

I apologise as I seem to be all take and not much give on this
forum at the moment; I’m trying to do a lot of learning very
quickly. Someone ask a question about HDMI so that I can feel useful!

Today’s question is what appears to be a contradiction in IEC
61000-3-2:2014.

  * The customers equipment is a triac controlled high-power PSU
for welding plastic parts together using resistance heater coils
  * Power is over 1kW and the customer is suggesting that it is
“professional equipment” which, according to Clause 7, means
that harmonic “limits are not specified in this standard”
  * Flowchart in Clause 7 says that Clause 6.1 for allowed
control methods still applies even to equipment with no limits
  * Clause 6.1 says symmetrical control methods which produce
large low order harmonics (arguably this applies to triac
control) that are used to power heating elements (applicable)
provided that either input power is less than 200W (it isn’t)
or the harmonic limits of Table 3 apply
  * Clause 6.1 also says that symmetrical control for
professional equipment is OK provided one of the “above
conditions” is fulfilled (which it is, see previous bullet)

So we’ve gone from Clause 7 saying no limits apply to Clause 6
saying that Class D equipment limits apply.

However the flowchart in Clause 7 suggests that just by being
exempt from Clause 7 limits means it automatically conforms to
61000-3-2

I feel like I’m going in circles. Does anyone have any insight
that might help?

Much appreciated,

James

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A

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[Michael Violette]

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Michael Violette, P.E.
Director
American Certification Body
mi...@wll.com
+1 240-401-1388




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Re: [PSES] IEC 61000-3-2 Confusion

[James Pawson (U3C)]

It was the symmetrical control for the powering of heating elements part that 
was the previous condition that was fulfilled. 

Hope this helps
James

 John Woodgate wrote 

>OK, I've sent a digest to the committee chair. Meanwhile, I noticed 
>something that I don't quite understand:
>
>You say that "Clause 6.1 also says that symmetrical control for 
>professional equipment is OK provided one of the “above conditions” is 
>fulfilled (which it is, see previous bullet)"
>
>Which is the 'above condition' that the welder meets?
>
>John Woodgate OOO-Own Opinions Only
>J M Woodgate and Associates www.woodjohn.uk
>Rayleigh, Essex UK
>
>On 2017-10-11 17:08, James Pawson (U3C) wrote:
>>
>> Hello John,
>>
>> It uses phase angle control hence the concern about the harmonics 
>> generated.
>>
>> Manufacturer specs are single phase, 230V nominal, 3kW.
>>
>> Typically used at less than a 15% duty cycle, often less, in an 
>> industrial environment or powered from a generator.
>>
>> My *feeling* is that should be classified as professional equipment 
>> and exempted under Clause 7 but the IEV has 0 search for feelings.
>>
>> Thanks for your help
>>
>> James
>>
>> *From:*John Woodgate [mailto:j...@woodjohn.uk]
>> *Sent:* 11 October 2017 16:49
>> *To:* EMC-PSTC@LISTSERV.IEEE.ORG
>> *Subject:* Re: [PSES] IEC 61000-3-2 Confusion
>>
>> I agree that there appears to be a need for clarification, and I will 
>> take that up with the committee responsible. But for your particular 
>> case, what is critical is the nature of the 'triac control'. Is it 
>> phase-angle control, or 'burst firing' or something else?
>>
>> John Woodgate OOO-Own Opinions Only
>> J M Woodgate and Associateswww.woodjohn.uk 
>> Rayleigh, Essex UK
>>
>> On 2017-10-11 15:01, James Pawson (U3C) wrote:
>>
>> Hi folks,
>>
>> I apologise as I seem to be all take and not much give on this
>> forum at the moment; I’m trying to do a lot of learning very
>> quickly. Someone ask a question about HDMI so that I can feel useful!
>>
>> Today’s question is what appears to be a contradiction in IEC
>> 61000-3-2:2014.
>>
>>   * The customers equipment is a triac controlled high-power PSU
>> for welding plastic parts together using resistance heater coils
>>   * Power is over 1kW and the customer is suggesting that it is
>> “professional equipment” which, according to Clause 7, means
>> that harmonic “limits are not specified in this standard”
>>   * Flowchart in Clause 7 says that Clause 6.1 for allowed control
>> methods still applies even to equipment with no limits
>>   * Clause 6.1 says symmetrical control methods which produce
>> large low order harmonics (arguably this applies to triac
>> control) that are used to power heating elements (applicable)
>> provided that either input power is less than 200W (it isn’t)
>> or the harmonic limits of Table 3 apply
>>   * Clause 6.1 also says that symmetrical control for professional
>> equipment is OK provided one of the “above conditions” is
>> fulfilled (which it is, see previous bullet)
>>
>> So we’ve gone from Clause 7 saying no limits apply to Clause 6
>> saying that Class D equipment limits apply.
>>
>> However the flowchart in Clause 7 suggests that just by being
>> exempt from Clause 7 limits means it automatically conforms to
>> 61000-3-2
>>
>> I feel like I’m going in circles. Does anyone have any insight
>> that might help?
>>
>> Much appreciated,
>>
>> James
>>
>> -
>> 
>>
>> This message is from the IEEE Product Safety Engineering Society
>> emc-pstc discussion list. To post a message to the list, send your
>> e-mail to mailto:emc-p...@ieee.org>>
>>
>> All emc-pstc postings are archived and searchable on the web at:
>> http://www.ieee-pses.org/emc-pstc.html
>>
>> Attachments are not permitted but the IEEE PSES Online Communities
>> site at http://product-compliance.oc.ieee.org/ can be used for
>> graphics (in well-used formats), large files, etc.
>>
>> Website: http://www.ieee-pses.org/
>> Instructions: http://www.ieee-pses.org/list.html (including how to
>> unsubscribe)
>> List rules: http://www.ieee-pses.org/listrules.html
>>
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>>
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>> David Heald mailto:dhe...@gmail.com>>
>>
>> -
>> 
>>
>> This message is from the IEEE Product Safety Engineering Society 
>> emc-pstc discussion list. To post a message to the list, send your 
>> e-mail to mailto:emc-p...@ieee.org>>
>>
>> All emc-pstc postings are archived an

Re: [PSES] IEC 61000-3-2 Confusion

[John Woodgate]

OK, I've sent a digest to the committee chair. Meanwhile, I noticed 
something that I don't quite understand:


You say that "Clause 6.1 also says that symmetrical control for 
professional equipment is OK provided one of the “above conditions” is 
fulfilled (which it is, see previous bullet)"


Which is the 'above condition' that the welder meets?

John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates www.woodjohn.uk
Rayleigh, Essex UK

On 2017-10-11 17:08, James Pawson (U3C) wrote:


Hello John,

It uses phase angle control hence the concern about the harmonics 
generated.


Manufacturer specs are single phase, 230V nominal, 3kW.

Typically used at less than a 15% duty cycle, often less, in an 
industrial environment or powered from a generator.


My *feeling* is that should be classified as professional equipment 
and exempted under Clause 7 but the IEV has 0 search for feelings.


Thanks for your help

James

*From:*John Woodgate [mailto:j...@woodjohn.uk]
*Sent:* 11 October 2017 16:49
*To:* EMC-PSTC@LISTSERV.IEEE.ORG
*Subject:* Re: [PSES] IEC 61000-3-2 Confusion

I agree that there appears to be a need for clarification, and I will 
take that up with the committee responsible. But for your particular 
case, what is critical is the nature of the 'triac control'. Is it 
phase-angle control, or 'burst firing' or something else?


John Woodgate OOO-Own Opinions Only
J M Woodgate and Associateswww.woodjohn.uk 
Rayleigh, Essex UK

On 2017-10-11 15:01, James Pawson (U3C) wrote:

Hi folks,

I apologise as I seem to be all take and not much give on this
forum at the moment; I’m trying to do a lot of learning very
quickly. Someone ask a question about HDMI so that I can feel useful!

Today’s question is what appears to be a contradiction in IEC
61000-3-2:2014.

  * The customers equipment is a triac controlled high-power PSU
for welding plastic parts together using resistance heater coils
  * Power is over 1kW and the customer is suggesting that it is
“professional equipment” which, according to Clause 7, means
that harmonic “limits are not specified in this standard”
  * Flowchart in Clause 7 says that Clause 6.1 for allowed control
methods still applies even to equipment with no limits
  * Clause 6.1 says symmetrical control methods which produce
large low order harmonics (arguably this applies to triac
control) that are used to power heating elements (applicable)
provided that either input power is less than 200W (it isn’t)
or the harmonic limits of Table 3 apply
  * Clause 6.1 also says that symmetrical control for professional
equipment is OK provided one of the “above conditions” is
fulfilled (which it is, see previous bullet)

So we’ve gone from Clause 7 saying no limits apply to Clause 6
saying that Class D equipment limits apply.

However the flowchart in Clause 7 suggests that just by being
exempt from Clause 7 limits means it automatically conforms to
61000-3-2

I feel like I’m going in circles. Does anyone have any insight
that might help?

Much appreciated,

James

-


This message is from the IEEE Product Safety Engineering Society
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Attachments are not permitted but the IEEE PSES Online Communities
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Website: http://www.ieee-pses.org/
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unsubscribe)
List rules: http://www.ieee-pses.org/listrules.html

For help, send mail to the list administrators:
Scott Douglas mailto:sdoug...@ieee.org>>
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Jim Bacher mailto:j.bac...@ieee.org>>
David Heald mailto:dhe...@gmail.com>>

-


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Scott Dou

Re: [PSES] NEMA 5-20P with IEC 60320 C13

[Nyffenegger, Dave]

Not sure if your question is specific to NEC or not.  There are other 
standards, for example UL 508A that have similar rules that are not specific to 
circuit sizes.

And the rules are not all straight forward as they apply to conductor sizing, 
branch circuit protection, connectors/components, etc. and the type of loads.   
For example NFPA 70 210.20 (A) states  “Where a branch circuit supplies 
continuous loads or any combination of continuous and noncontinuous loads, the 
rating of the overcurrent device shall not be less than the noncontinuous load 
plus 125 percent of the continuous load.  Exception: Where the assembly, 
including the overcurrent devices protecting the branch circuit(s), is listed 
for operationat 100 percent of its rating, the ampere rating of the overcurrent 
device shall be permitted to be not less than the sum of the continuous load 
plus the noncontinuous load.” without mentioning anything about circuit size.

-Dave

From: Kunde, Brian [mailto:brian_ku...@lecotc.com]
Sent: Wednesday, October 11, 2017 3:02 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] NEMA 5-20P with IEC 60320 C13

One last quick question, if I may, while we are all up on the NEC.

Just to confirm, the 80% rule only applies to 15A, 20A, and 30A branch 
circuits. 40A and 50A branch circuits do not have the 80% rule, even in a 
multiple-outlet configuration? I know these larger circuits are generally 
dedicated circuits, but that is how the rules read in the NEC 210.23(C). Unless 
I’m missing something.

Thanks bunches.
The Other Brian

From: John Woodgate [mailto:j...@woodjohn.uk]
Sent: Wednesday, October 11, 2017 2:57 PM
To: Kunde, Brian; EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] NEMA 5-20P with IEC 60320 C13


Yes, of course quite a thin conductor will carry enough current to operate the 
protection, because it doesn't have time to get seriously hot.

John Woodgate OOO-Own Opinions Only

J M Woodgate and Associates www.woodjohn.uk

Rayleigh, Essex UK
On 2017-10-11 19:35, Kunde, Brian wrote:

I know I started this thread, so I'm going to circuit back via another 
direction.



The NEC allows a product with an 18 awg power cord (rated 10 amps), a 15 amp 
plug, and C13 IEC connector (15 amp) to be plugged into a 15 amp branch 
circuit. OH, you can also plug it into a 20 amp branch circuit because the 
receptacles will accept a 15 amp plug. So what protects the freakishly small 18 
awg power cord from bursting into flames in an overload condition?  Must be the 
OverCurrent Protection device in the product itself. Correct?



So back to original questions, can I use a power cord with a 20 amp plug (NEMA 
5-20P), 12 awg wire, and 15 amp IEC C13 connector on a product that draws 15 
amps and has a double pole 15 amp OCPD?  With the same logic above, the OCP 
device is protecting the power cord.



Would you allow this?  Then again, your you allow a 18awg power cord to be used 
on a 15 amp circuit?  The NEC says it is ok.



Thanks,

The Other Brian



-Original Message-

From: Nyffenegger, Dave [mailto:dave.nyffeneg...@bhemail.com]

Sent: Wednesday, October 11, 2017 1:30 PM

To: EMC-PSTC@LISTSERV.IEEE.ORG

Subject: Re: [PSES] NEMA 5-20P with IEC 60320 C13



Had a condo  with  a smallish through-the-wall A/C unit with NEMA 5-15P plug.  
In the room on one side of the unit was a dedicated 20A single outlet for the 
A/C unit.  In the room on the other side easily within reach of the cord was a 
standard duplex outlet on the room circuit.  Guess which one the A/C was 
plugged into?



-Dave



-Original Message-

From: Pete Perkins [mailto:0061f3f32d0c-dmarc-requ...@ieee.org]

Sent: Wednesday, October 11, 2017 1:04 PM

To: EMC-PSTC@LISTSERV.IEEE.ORG

Subject: Re: [PSES] NEMA 5-20P with IEC 60320 C13



Ralph, Ted et al,



Dunno how many times I have had this conversation with the project 
engineer who wants to use the full rated current from the duplex outlet (and 
not leave any for the other user who plugs into that outlet - which gives rise 
to the 80% rule) - except if they want to specify in the installation that the 
user must have an expensive electrician install a special dedicated outlet 
(only one plug available to the user on that CB controlled circuit); which 
gives rise to the marketing folks nixing the idea.  :>)Carry on! As you 
were doing...



:>) br,  Pete



Peter E Perkins, PE

Principal Product Safety & Regulatory Affairs Consultant PO Box 23427 Tigard, 
ORe  97281-3427



503/452-1201



p.perk...@ieee.org



-Original Message-

From: Ralph McDiarmid [mailto:ralph.mcdiar...@schneider-electric.com]

Sent: Wednesday, October 11, 2017 9:05 AM

To: EMC-PSTC@LISTSERV.IEEE.ORG

Subject: Re: [PSES] NEMA 5-20P with IEC 60320 C13



Sounds like an example of the 125% rule for continuous (>3hr) cu

Re: [PSES] NEMA 5-20P with IEC 60320 C13

[Ralph McDiarmid]

NEC article 210 writes about “branch circuits” up to 600V.  I didn’t see a 
limit on current, so we’ve always applied it to OCP and ampacity for all 
conductors on circuits where the current is expected to be “continuous”, as 
defined in the code.  ( we go up to 2000A on a 575V circuit on a custom 
transformer, dedicated circuit)

>From chapter II:  "Where a branch circuit supplies continuous loads or any 
>combination of continuous and non-continuous loads, the minimum branch-circuit 
>conductor size shall have an allowable ampacity not less than the 
>non-continuous load plus 125 percent of the continuous load."

It's easy for our equipment where it is always supplied by a dedicated "branch 
circuit" (often a dedicated transformer) and current is continuous by 
definition. (> 3hrs)

Strictly speaking,  it's a 125% rule, not an 80% rule

Ralph McDiarmid
Product Compliance
Engineering
Solar Business
Schneider Electric


From: Kunde, Brian [mailto:brian_ku...@lecotc.com] 
Sent: Wednesday, October 11, 2017 12:02 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] NEMA 5-20P with IEC 60320 C13

One last quick question, if I may, while we are all up on the NEC.

Just to confirm, the 80% rule only applies to 15A, 20A, and 30A branch 
circuits. 40A and 50A branch circuits do not have the 80% rule, even in a 
multiple-outlet configuration? I know these larger circuits are generally 
dedicated circuits, but that is how the rules read in the NEC 210.23(C). Unless 
I’m missing something. 

Thanks bunches.
The Other Brian

From: John Woodgate [mailto:j...@woodjohn.uk] 
Sent: Wednesday, October 11, 2017 2:57 PM
To: Kunde, Brian; mailto:EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] NEMA 5-20P with IEC 60320 C13

Yes, of course quite a thin conductor will carry enough current to operate the 
protection, because it doesn't have time to get seriously hot.
John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates http://www.woodjohn.uk
Rayleigh, Essex UK
On 2017-10-11 19:35, Kunde, Brian wrote:
I know I started this thread, so I'm going to circuit back via another 
direction.

The NEC allows a product with an 18 awg power cord (rated 10 amps), a 15 amp 
plug, and C13 IEC connector (15 amp) to be plugged into a 15 amp branch 
circuit. OH, you can also plug it into a 20 amp branch circuit because the 
receptacles will accept a 15 amp plug. So what protects the freakishly small 18 
awg power cord from bursting into flames in an overload condition?  Must be the 
OverCurrent Protection device in the product itself. Correct?

So back to original questions, can I use a power cord with a 20 amp plug (NEMA 
5-20P), 12 awg wire, and 15 amp IEC C13 connector on a product that draws 15 
amps and has a double pole 15 amp OCPD?  With the same logic above, the OCP 
device is protecting the power cord.

Would you allow this?  Then again, your you allow a 18awg power cord to be used 
on a 15 amp circuit?  The NEC says it is ok.

Thanks,
The Other Brian

-Original Message-
From: Nyffenegger, Dave [mailto:dave.nyffeneg...@bhemail.com]
Sent: Wednesday, October 11, 2017 1:30 PM
To: mailto:EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] NEMA 5-20P with IEC 60320 C13

Had a condo  with  a smallish through-the-wall A/C unit with NEMA 5-15P plug.  
In the room on one side of the unit was a dedicated 20A single outlet for the 
A/C unit.  In the room on the other side easily within reach of the cord was a 
standard duplex outlet on the room circuit.  Guess which one the A/C was 
plugged into?

-Dave

-Original Message-
From: Pete Perkins [mailto:0061f3f32d0c-dmarc-requ...@ieee.org]
Sent: Wednesday, October 11, 2017 1:04 PM
To: mailto:EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] NEMA 5-20P with IEC 60320 C13

Ralph, Ted et al,

    Dunno how many times I have had this conversation with the project 
engineer who wants to use the full rated current from the duplex outlet (and 
not leave any for the other user who plugs into that outlet - which gives rise 
to the 80% rule) - except if they want to specify in the installation that the 
user must have an expensive electrician install a special dedicated outlet 
(only one plug available to the user on that CB controlled circuit); which 
gives rise to the marketing folks nixing the idea.  :>)    Carry on! As you 
were doing...

:>) br,  Pete

Peter E Perkins, PE
Principal Product Safety & Regulatory Affairs Consultant PO Box 23427 Tigard, 
ORe  97281-3427

503/452-1201

mailto:p.perk...@ieee.org

-Original Message-
From: Ralph McDiarmid [mailto:ralph.mcdiar...@schneider-electric.com]
Sent: Wednesday, October 11, 2017 9:05 AM
To: mailto:EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] NEMA 5-20P with IEC 60320 C13

Sounds like an example of the 125% rule for continuous (>3hr) current.  (20/16)

Ralph McDiarmid
Product Compliance
Engineering
Solar Business
Schneider Electric


From: Ted Eckert [mailto:07cf6ebeab9d-dmarc-requ...@ieee.org]
Sent: Wednesday, Oct

Re: [PSES] NEMA 5-20P with IEC 60320 C13

[Kunde, Brian]

One last quick question, if I may, while we are all up on the NEC.

Just to confirm, the 80% rule only applies to 15A, 20A, and 30A branch 
circuits. 40A and 50A branch circuits do not have the 80% rule, even in a 
multiple-outlet configuration? I know these larger circuits are generally 
dedicated circuits, but that is how the rules read in the NEC 210.23(C). Unless 
I’m missing something.

Thanks bunches.
The Other Brian

From: John Woodgate [mailto:j...@woodjohn.uk]
Sent: Wednesday, October 11, 2017 2:57 PM
To: Kunde, Brian; EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] NEMA 5-20P with IEC 60320 C13


Yes, of course quite a thin conductor will carry enough current to operate the 
protection, because it doesn't have time to get seriously hot.

John Woodgate OOO-Own Opinions Only

J M Woodgate and Associates www.woodjohn.uk

Rayleigh, Essex UK
On 2017-10-11 19:35, Kunde, Brian wrote:

I know I started this thread, so I'm going to circuit back via another 
direction.



The NEC allows a product with an 18 awg power cord (rated 10 amps), a 15 amp 
plug, and C13 IEC connector (15 amp) to be plugged into a 15 amp branch 
circuit. OH, you can also plug it into a 20 amp branch circuit because the 
receptacles will accept a 15 amp plug. So what protects the freakishly small 18 
awg power cord from bursting into flames in an overload condition?  Must be the 
OverCurrent Protection device in the product itself. Correct?



So back to original questions, can I use a power cord with a 20 amp plug (NEMA 
5-20P), 12 awg wire, and 15 amp IEC C13 connector on a product that draws 15 
amps and has a double pole 15 amp OCPD?  With the same logic above, the OCP 
device is protecting the power cord.



Would you allow this?  Then again, your you allow a 18awg power cord to be used 
on a 15 amp circuit?  The NEC says it is ok.



Thanks,

The Other Brian



-Original Message-

From: Nyffenegger, Dave [mailto:dave.nyffeneg...@bhemail.com]

Sent: Wednesday, October 11, 2017 1:30 PM

To: EMC-PSTC@LISTSERV.IEEE.ORG

Subject: Re: [PSES] NEMA 5-20P with IEC 60320 C13



Had a condo  with  a smallish through-the-wall A/C unit with NEMA 5-15P plug.  
In the room on one side of the unit was a dedicated 20A single outlet for the 
A/C unit.  In the room on the other side easily within reach of the cord was a 
standard duplex outlet on the room circuit.  Guess which one the A/C was 
plugged into?



-Dave



-Original Message-

From: Pete Perkins [mailto:0061f3f32d0c-dmarc-requ...@ieee.org]

Sent: Wednesday, October 11, 2017 1:04 PM

To: EMC-PSTC@LISTSERV.IEEE.ORG

Subject: Re: [PSES] NEMA 5-20P with IEC 60320 C13



Ralph, Ted et al,



Dunno how many times I have had this conversation with the project 
engineer who wants to use the full rated current from the duplex outlet (and 
not leave any for the other user who plugs into that outlet - which gives rise 
to the 80% rule) - except if they want to specify in the installation that the 
user must have an expensive electrician install a special dedicated outlet 
(only one plug available to the user on that CB controlled circuit); which 
gives rise to the marketing folks nixing the idea.  :>)Carry on! As you 
were doing...



:>) br,  Pete



Peter E Perkins, PE

Principal Product Safety & Regulatory Affairs Consultant PO Box 23427 Tigard, 
ORe  97281-3427



503/452-1201



p.perk...@ieee.org



-Original Message-

From: Ralph McDiarmid [mailto:ralph.mcdiar...@schneider-electric.com]

Sent: Wednesday, October 11, 2017 9:05 AM

To: EMC-PSTC@LISTSERV.IEEE.ORG

Subject: Re: [PSES] NEMA 5-20P with IEC 60320 C13



Sounds like an example of the 125% rule for continuous (>3hr) current.  (20/16)



Ralph McDiarmid

Product Compliance

Engineering

Solar Business

Schneider Electric





From: Ted Eckert [mailto:07cf6ebeab9d-dmarc-requ...@ieee.org]

Sent: Wednesday, October 11, 2017 5:50 AM

To: EMC-PSTC@LISTSERV.IEEE.ORG

Subject: Re: [PSES] NEMA 5-20P with IEC 60320 C13



NFPA 70 allows 20 A connectors to be used at 20 A under a number of 
circumstances. The derating issue only applies in certain cases. Just changing 
the rating doesn’t resolve the issue as it would eliminate already accepted 
safe use of the connectors at their full rating.



Ted Eckert

Microsoft Corporation



The opinions expressed are my own and do not necessarily reflect those of my 
employer.



From: John Woodgate [mailto:j...@woodjohn.uk]

Sent: Tuesday, October 10, 2017 11:21 PM

To: Ted Eckert 
; 
mailto:EMC-PSTC@LISTSERV.IEEE.ORG

Subject: Re: [PSES] NEMA 5-20P with IEC 60320 C13



Yes, it could be difficult to change to respecting the rated values, so how 
about respecting the de-rated values instead? Inst

Re: [PSES] NEMA 5-20P with IEC 60320 C13

[John Woodgate]

Yes, of course quite a thin conductor will carry enough current to 
operate the protection, because it doesn't have time to get seriously hot.


John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates www.woodjohn.uk
Rayleigh, Essex UK

On 2017-10-11 19:35, Kunde, Brian wrote:

I know I started this thread, so I'm going to circuit back via another 
direction.

The NEC allows a product with an 18 awg power cord (rated 10 amps), a 15 amp 
plug, and C13 IEC connector (15 amp) to be plugged into a 15 amp branch 
circuit. OH, you can also plug it into a 20 amp branch circuit because the 
receptacles will accept a 15 amp plug. So what protects the freakishly small 18 
awg power cord from bursting into flames in an overload condition?  Must be the 
OverCurrent Protection device in the product itself. Correct?

So back to original questions, can I use a power cord with a 20 amp plug (NEMA 
5-20P), 12 awg wire, and 15 amp IEC C13 connector on a product that draws 15 
amps and has a double pole 15 amp OCPD?  With the same logic above, the OCP 
device is protecting the power cord.

Would you allow this?  Then again, your you allow a 18awg power cord to be used 
on a 15 amp circuit?  The NEC says it is ok.

Thanks,
The Other Brian

-Original Message-
From: Nyffenegger, Dave [mailto:dave.nyffeneg...@bhemail.com]
Sent: Wednesday, October 11, 2017 1:30 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] NEMA 5-20P with IEC 60320 C13

Had a condo  with  a smallish through-the-wall A/C unit with NEMA 5-15P plug.  
In the room on one side of the unit was a dedicated 20A single outlet for the 
A/C unit.  In the room on the other side easily within reach of the cord was a 
standard duplex outlet on the room circuit.  Guess which one the A/C was 
plugged into?

-Dave

-Original Message-
From: Pete Perkins [mailto:0061f3f32d0c-dmarc-requ...@ieee.org]
Sent: Wednesday, October 11, 2017 1:04 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] NEMA 5-20P with IEC 60320 C13

Ralph, Ted et al,

 Dunno how many times I have had this conversation with the project 
engineer who wants to use the full rated current from the duplex outlet (and not 
leave any for the other user who plugs into that outlet - which gives rise to the 
80% rule) - except if they want to specify in the installation that the user must 
have an expensive electrician install a special dedicated outlet (only one plug 
available to the user on that CB controlled circuit); which gives rise to the 
marketing folks nixing the idea.  :>)Carry on! As you were doing...

:>) br,  Pete

Peter E Perkins, PE
Principal Product Safety & Regulatory Affairs Consultant PO Box 23427 Tigard, 
ORe  97281-3427

503/452-1201

p.perk...@ieee.org

-Original Message-
From: Ralph McDiarmid [mailto:ralph.mcdiar...@schneider-electric.com]
Sent: Wednesday, October 11, 2017 9:05 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] NEMA 5-20P with IEC 60320 C13

Sounds like an example of the 125% rule for continuous (>3hr) current.  (20/16)

Ralph McDiarmid
Product Compliance
Engineering
Solar Business
Schneider Electric


From: Ted Eckert [mailto:07cf6ebeab9d-dmarc-requ...@ieee.org]
Sent: Wednesday, October 11, 2017 5:50 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] NEMA 5-20P with IEC 60320 C13

NFPA 70 allows 20 A connectors to be used at 20 A under a number of 
circumstances. The derating issue only applies in certain cases. Just changing 
the rating doesn’t resolve the issue as it would eliminate already accepted 
safe use of the connectors at their full rating.

Ted Eckert
Microsoft Corporation

The opinions expressed are my own and do not necessarily reflect those of my 
employer.

From: John Woodgate [mailto:j...@woodjohn.uk]
Sent: Tuesday, October 10, 2017 11:21 PM
To: Ted Eckert ; 
mailto:EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] NEMA 5-20P with IEC 60320 C13

Yes, it could be difficult to change to respecting the rated values, so how 
about respecting the de-rated values instead? Instead of saying that you can 
only use this 20 A connector up to 16 A, call it a 16 A connector?
John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates 
https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.woodjohn.uk&data=02%7C01%7CTed.Eckert%40MICROSOFT.COM%7C6f5a4a13ae97469548f108d510703247%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C636432996434092831&sdata=vbIPUaUZRYojTmRGRu9LrQO4Emqy7f8wN1OY8mY%2BQFg%3D&reserved=0
Rayleigh, Essex UK
On 2017-10-10 21:57, Ted Eckert wrote:
The various clauses of NFPA 70 are reviewed, challenged, debated, argued and 
rewritten. I don’t think the clause in question remains because nobody has 
challenged it. Part of the issue is that the electrical infrastructure in the 
U.S. has been developed around this rule. If affects circuit breaker trip 
curves, conduit fill, wire sizes and rating and many other aspects of a 
building’s electrical sy

Re: [PSES] IEC 61000-3-2 Confusion

[John Woodgate]

I don't know for sure. I was told that the low-frequency emission 
standards apply whether they are cited in a Generic or not.  61000-6-3 
isn't restricted to 'residential, it includes 'commercial and light 
industrial, which is why 61000-3-11 and -12 are cited. Maybe 61000-6-3 
assumes a dedicated MV/LV transformer.


John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates www.woodjohn.uk
Rayleigh, Essex UK

On 2017-10-11 19:28, Ralph McDiarmid wrote:

That is an interesting technical point.  Notice that EN61000-6-3 (generic 
residential) calls out 61000-3-2, -3, -11  and -12, but EN61000-6-4 
(industrial) does not.

Presumably,  EN61000-6-4 makes full provision for the apparatus ?

Ralph McDiarmid
Product Compliance
Engineering
Solar Business
Schneider Electric


From: John Woodgate [mailto:j...@woodjohn.uk]
Sent: Wednesday, October 11, 2017 10:10 AM
To: Ralph McDiarmid ; 
EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] IEC 61000-3-2 Confusion

61000-3-2, -3, -11  and -12 do not have to be cited in the Generics; they apply 
independently. 61000-3-4 assumes a dedicated MV/LV transformer, but the product 
is only 3 kW, so one can't assume that.
John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates http://www.woodjohn.uk
Rayleigh, Essex UK
On 2017-10-11 17:26, Ralph McDiarmid wrote:
I wonder if your customer's triac equipment falls under the EN61000-6-4 (EMC) 
Emission standard for
industrial environments?   I didn't see 61000-3-2 called out in that generic 
standard.

Ralph McDiarmid
Product Compliance
Engineering
Solar Business
Schneider Electric


From: James Pawson (U3C) [mailto:ja...@unit3compliance.co.uk]
Sent: Wednesday, October 11, 2017 9:08 AM
To: mailto:EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] IEC 61000-3-2 Confusion

Hello John,

It uses phase angle control hence the concern about the harmonics generated.
Manufacturer specs are single phase, 230V nominal, 3kW.
Typically used at less than a 15% duty cycle, often less, in an industrial 
environment or powered from a generator.

My *feeling* is that should be classified as professional equipment and 
exempted under Clause 7 but the IEV has 0 search for feelings.

Thanks for your help
James


From: John Woodgate [mailto:j...@woodjohn.uk]
Sent: 11 October 2017 16:49
To: mailto:EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] IEC 61000-3-2 Confusion

I agree that there appears to be a need for clarification, and I will take that 
up with the committee responsible. But for your particular case, what is 
critical is the nature of the 'triac control'. Is it phase-angle control, or 
'burst firing' or something else?
John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates http://www.woodjohn.uk
Rayleigh, Essex UK
On 2017-10-11 15:01, James Pawson (U3C) wrote:
Hi folks,
  
I apologise as I seem to be all take and not much give on this forum at the moment; I'm trying to do a lot of learning very quickly. Someone ask a question about HDMI so that I can feel useful!
  
Today's question is what appears to be a contradiction in IEC 61000-3-2:2014.
  
. The customers equipment is a triac controlled high-power PSU for welding plastic parts together using resistance heater coils

. Power is over 1kW and the customer is suggesting that it is "professional equipment" 
which, according to Clause 7, means that harmonic "limits are not specified in this 
standard"
. Flowchart in Clause 7 says that Clause 6.1 for allowed control methods still 
applies even to equipment with no limits
. Clause 6.1 says symmetrical control methods which produce large low order 
harmonics (arguably this applies to triac control) that are used to power 
heating elements (applicable) provided that either input power is less than 
200W (it isn't) or the harmonic limits of Table 3 apply
. Clause 6.1 also says that symmetrical control for professional equipment is OK provided 
one of the "above conditions" is fulfilled (which it is, see previous bullet)
  
So we've gone from Clause 7 saying no limits apply to Clause 6 saying that Class D equipment limits apply.

However the flowchart in Clause 7 suggests that just by being exempt from 
Clause 7 limits means it automatically conforms to 61000-3-2
  
I feel like I'm going in circles. Does anyone have any insight that might help?
  
Much appreciated,

James
  
  
-


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Re: [PSES] NEMA 5-20P with IEC 60320 C13

[Ralph McDiarmid]

Since you're asking for an opinion and since IEC would allow it, I think it's 
reasonable to allow it in N.Am too.  There is no apparent hazard; the 15A OCPD 
adequately protects both the connector and the cordage.

Ralph McDiarmid
Product Compliance
Engineering
Solar Business
Schneider Electric


-Original Message-
From: Kunde, Brian [mailto:brian_ku...@lecotc.com] 
Sent: Wednesday, October 11, 2017 11:35 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] NEMA 5-20P with IEC 60320 C13

I know I started this thread, so I'm going to circuit back via another 
direction.

The NEC allows a product with an 18 awg power cord (rated 10 amps), a 15 amp 
plug, and C13 IEC connector (15 amp) to be plugged into a 15 amp branch 
circuit. OH, you can also plug it into a 20 amp branch circuit because the 
receptacles will accept a 15 amp plug. So what protects the freakishly small 18 
awg power cord from bursting into flames in an overload condition?  Must be the 
OverCurrent Protection device in the product itself. Correct?

So back to original questions, can I use a power cord with a 20 amp plug (NEMA 
5-20P), 12 awg wire, and 15 amp IEC C13 connector on a product that draws 15 
amps and has a double pole 15 amp OCPD?  With the same logic above, the OCP 
device is protecting the power cord.

Would you allow this?  Then again, your you allow a 18awg power cord to be used 
on a 15 amp circuit?  The NEC says it is ok.

Thanks,
The Other Brian

-Original Message-
From: Nyffenegger, Dave [mailto:dave.nyffeneg...@bhemail.com]
Sent: Wednesday, October 11, 2017 1:30 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] NEMA 5-20P with IEC 60320 C13

Had a condo  with  a smallish through-the-wall A/C unit with NEMA 5-15P plug.  
In the room on one side of the unit was a dedicated 20A single outlet for the 
A/C unit.  In the room on the other side easily within reach of the cord was a 
standard duplex outlet on the room circuit.  Guess which one the A/C was 
plugged into?

-Dave

-Original Message-
From: Pete Perkins [mailto:0061f3f32d0c-dmarc-requ...@ieee.org]
Sent: Wednesday, October 11, 2017 1:04 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] NEMA 5-20P with IEC 60320 C13

Ralph, Ted et al,

Dunno how many times I have had this conversation with the project 
engineer who wants to use the full rated current from the duplex outlet (and 
not leave any for the other user who plugs into that outlet - which gives rise 
to the 80% rule) - except if they want to specify in the installation that the 
user must have an expensive electrician install a special dedicated outlet 
(only one plug available to the user on that CB controlled circuit); which 
gives rise to the marketing folks nixing the idea.  :>)Carry on! As you 
were doing...

:>) br,  Pete

Peter E Perkins, PE
Principal Product Safety & Regulatory Affairs Consultant PO Box 23427 Tigard, 
ORe  97281-3427

503/452-1201

p.perk...@ieee.org

-Original Message-
From: Ralph McDiarmid [mailto:ralph.mcdiar...@schneider-electric.com]
Sent: Wednesday, October 11, 2017 9:05 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] NEMA 5-20P with IEC 60320 C13

Sounds like an example of the 125% rule for continuous (>3hr) current.  (20/16)

Ralph McDiarmid
Product Compliance
Engineering
Solar Business
Schneider Electric


From: Ted Eckert [mailto:07cf6ebeab9d-dmarc-requ...@ieee.org]
Sent: Wednesday, October 11, 2017 5:50 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] NEMA 5-20P with IEC 60320 C13

NFPA 70 allows 20 A connectors to be used at 20 A under a number of 
circumstances. The derating issue only applies in certain cases. Just changing 
the rating doesn’t resolve the issue as it would eliminate already accepted 
safe use of the connectors at their full rating.

Ted Eckert
Microsoft Corporation

The opinions expressed are my own and do not necessarily reflect those of my 
employer.

From: John Woodgate [mailto:j...@woodjohn.uk]
Sent: Tuesday, October 10, 2017 11:21 PM
To: Ted Eckert ; 
mailto:EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] NEMA 5-20P with IEC 60320 C13

Yes, it could be difficult to change to respecting the rated values, so how 
about respecting the de-rated values instead? Instead of saying that you can 
only use this 20 A connector up to 16 A, call it a 16 A connector?
John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates 
https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.woodjohn.uk&data=02%7C01%7CTed.Eckert%40MICROSOFT.COM%7C6f5a4a13ae97469548f108d510703247%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C636432996434092831&sdata=vbIPUaUZRYojTmRGRu9LrQO4Emqy7f8wN1OY8mY%2BQFg%3D&reserved=0
Rayleigh, Essex UK
On 2017-10-10 21:57, Ted Eckert wrote:
The various clauses of NFPA 70 are reviewed, challenged, debated, argued and 
rewritten. I don’t think the clause in question remains because nobody has 
challenged it. Part of the issue is

Re: [PSES] NEMA 5-20P with IEC 60320 C13

[Kunde, Brian]

I know I started this thread, so I'm going to circuit back via another 
direction.

The NEC allows a product with an 18 awg power cord (rated 10 amps), a 15 amp 
plug, and C13 IEC connector (15 amp) to be plugged into a 15 amp branch 
circuit. OH, you can also plug it into a 20 amp branch circuit because the 
receptacles will accept a 15 amp plug. So what protects the freakishly small 18 
awg power cord from bursting into flames in an overload condition?  Must be the 
OverCurrent Protection device in the product itself. Correct?

So back to original questions, can I use a power cord with a 20 amp plug (NEMA 
5-20P), 12 awg wire, and 15 amp IEC C13 connector on a product that draws 15 
amps and has a double pole 15 amp OCPD?  With the same logic above, the OCP 
device is protecting the power cord.

Would you allow this?  Then again, your you allow a 18awg power cord to be used 
on a 15 amp circuit?  The NEC says it is ok.

Thanks,
The Other Brian

-Original Message-
From: Nyffenegger, Dave [mailto:dave.nyffeneg...@bhemail.com]
Sent: Wednesday, October 11, 2017 1:30 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] NEMA 5-20P with IEC 60320 C13

Had a condo  with  a smallish through-the-wall A/C unit with NEMA 5-15P plug.  
In the room on one side of the unit was a dedicated 20A single outlet for the 
A/C unit.  In the room on the other side easily within reach of the cord was a 
standard duplex outlet on the room circuit.  Guess which one the A/C was 
plugged into?

-Dave

-Original Message-
From: Pete Perkins [mailto:0061f3f32d0c-dmarc-requ...@ieee.org]
Sent: Wednesday, October 11, 2017 1:04 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] NEMA 5-20P with IEC 60320 C13

Ralph, Ted et al,

Dunno how many times I have had this conversation with the project 
engineer who wants to use the full rated current from the duplex outlet (and 
not leave any for the other user who plugs into that outlet - which gives rise 
to the 80% rule) - except if they want to specify in the installation that the 
user must have an expensive electrician install a special dedicated outlet 
(only one plug available to the user on that CB controlled circuit); which 
gives rise to the marketing folks nixing the idea.  :>)Carry on! As you 
were doing...

:>) br,  Pete

Peter E Perkins, PE
Principal Product Safety & Regulatory Affairs Consultant PO Box 23427 Tigard, 
ORe  97281-3427

503/452-1201

p.perk...@ieee.org

-Original Message-
From: Ralph McDiarmid [mailto:ralph.mcdiar...@schneider-electric.com]
Sent: Wednesday, October 11, 2017 9:05 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] NEMA 5-20P with IEC 60320 C13

Sounds like an example of the 125% rule for continuous (>3hr) current.  (20/16)

Ralph McDiarmid
Product Compliance
Engineering
Solar Business
Schneider Electric


From: Ted Eckert [mailto:07cf6ebeab9d-dmarc-requ...@ieee.org]
Sent: Wednesday, October 11, 2017 5:50 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] NEMA 5-20P with IEC 60320 C13

NFPA 70 allows 20 A connectors to be used at 20 A under a number of 
circumstances. The derating issue only applies in certain cases. Just changing 
the rating doesn’t resolve the issue as it would eliminate already accepted 
safe use of the connectors at their full rating.

Ted Eckert
Microsoft Corporation

The opinions expressed are my own and do not necessarily reflect those of my 
employer.

From: John Woodgate [mailto:j...@woodjohn.uk]
Sent: Tuesday, October 10, 2017 11:21 PM
To: Ted Eckert ; 
mailto:EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] NEMA 5-20P with IEC 60320 C13

Yes, it could be difficult to change to respecting the rated values, so how 
about respecting the de-rated values instead? Instead of saying that you can 
only use this 20 A connector up to 16 A, call it a 16 A connector?
John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates 
https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.woodjohn.uk&data=02%7C01%7CTed.Eckert%40MICROSOFT.COM%7C6f5a4a13ae97469548f108d510703247%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C636432996434092831&sdata=vbIPUaUZRYojTmRGRu9LrQO4Emqy7f8wN1OY8mY%2BQFg%3D&reserved=0
Rayleigh, Essex UK
On 2017-10-10 21:57, Ted Eckert wrote:
The various clauses of NFPA 70 are reviewed, challenged, debated, argued and 
rewritten. I don’t think the clause in question remains because nobody has 
challenged it. Part of the issue is that the electrical infrastructure in the 
U.S. has been developed around this rule. If affects circuit breaker trip 
curves, conduit fill, wire sizes and rating and many other aspects of a 
building’s electrical system. If the rule were changed, would there be problems 
switching over? Would you have overheating in older structures where circuit 
breakers were replaced without updating wiring? Wold there be other effects of 
mixing 80% and 100% rated components? How many U.S. national standards w

Re: [PSES] IEC 61000-3-2 Confusion

[Ralph McDiarmid]

That is an interesting technical point.  Notice that EN61000-6-3 (generic 
residential) calls out 61000-3-2, -3, -11  and -12, but EN61000-6-4 
(industrial) does not.

Presumably,  EN61000-6-4 makes full provision for the apparatus ?

Ralph McDiarmid
Product Compliance
Engineering
Solar Business
Schneider Electric


From: John Woodgate [mailto:j...@woodjohn.uk] 
Sent: Wednesday, October 11, 2017 10:10 AM
To: Ralph McDiarmid ; 
EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] IEC 61000-3-2 Confusion

61000-3-2, -3, -11  and -12 do not have to be cited in the Generics; they apply 
independently. 61000-3-4 assumes a dedicated MV/LV transformer, but the product 
is only 3 kW, so one can't assume that.
John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates http://www.woodjohn.uk
Rayleigh, Essex UK
On 2017-10-11 17:26, Ralph McDiarmid wrote:
I wonder if your customer's triac equipment falls under the EN61000-6-4 (EMC) 
Emission standard for
industrial environments?   I didn't see 61000-3-2 called out in that generic 
standard.

Ralph McDiarmid
Product Compliance
Engineering
Solar Business
Schneider Electric


From: James Pawson (U3C) [mailto:ja...@unit3compliance.co.uk] 
Sent: Wednesday, October 11, 2017 9:08 AM
To: mailto:EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] IEC 61000-3-2 Confusion

Hello John,

It uses phase angle control hence the concern about the harmonics generated.
Manufacturer specs are single phase, 230V nominal, 3kW.
Typically used at less than a 15% duty cycle, often less, in an industrial 
environment or powered from a generator.

My *feeling* is that should be classified as professional equipment and 
exempted under Clause 7 but the IEV has 0 search for feelings.

Thanks for your help
James


From: John Woodgate [mailto:j...@woodjohn.uk] 
Sent: 11 October 2017 16:49
To: mailto:EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] IEC 61000-3-2 Confusion

I agree that there appears to be a need for clarification, and I will take that 
up with the committee responsible. But for your particular case, what is 
critical is the nature of the 'triac control'. Is it phase-angle control, or 
'burst firing' or something else?
John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates http://www.woodjohn.uk
Rayleigh, Essex UK
On 2017-10-11 15:01, James Pawson (U3C) wrote:
Hi folks,
 
I apologise as I seem to be all take and not much give on this forum at the 
moment; I'm trying to do a lot of learning very quickly. Someone ask a question 
about HDMI so that I can feel useful!
 
Today's question is what appears to be a contradiction in IEC 61000-3-2:2014.
 
. The customers equipment is a triac controlled high-power PSU for welding 
plastic parts together using resistance heater coils
. Power is over 1kW and the customer is suggesting that it is "professional 
equipment" which, according to Clause 7, means that harmonic "limits are not 
specified in this standard"
. Flowchart in Clause 7 says that Clause 6.1 for allowed control methods still 
applies even to equipment with no limits
. Clause 6.1 says symmetrical control methods which produce large low order 
harmonics (arguably this applies to triac control) that are used to power 
heating elements (applicable) provided that either input power is less than 
200W (it isn't) or the harmonic limits of Table 3 apply
. Clause 6.1 also says that symmetrical control for professional equipment is 
OK provided one of the "above conditions" is fulfilled (which it is, see 
previous bullet)
 
So we've gone from Clause 7 saying no limits apply to Clause 6 saying that 
Class D equipment limits apply.
However the flowchart in Clause 7 suggests that just by being exempt from 
Clause 7 limits means it automatically conforms to 61000-3-2
 
I feel like I'm going in circles. Does anyone have any insight that might help?
 
Much appreciated,
James
 
 
-

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This message is from the IEEE Product Safety Engineering Society emc-pstc 
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mailto:emc-p...@ieee.org
All 

Re: [PSES] NEMA 5-20P with IEC 60320 C13

[Nyffenegger, Dave]

For sure the A/C unit was not the original and it's possible the original had a 
NEMA 5-20P plug.  It's only cooling the small bedroom and bath.  The unit is 
rated 8.6A and the nameplate (picture of which is in my files) says in big bold 
letters USE ON SINGLE OUTLET CIRCUIT ONLY.

-Dave

-Original Message-
From: Pete Perkins [mailto:peperkin...@cs.com] 
Sent: Wednesday, October 11, 2017 1:39 PM
To: Nyffenegger, Dave; EMC-PSTC@LISTSERV.IEEE.ORG
Subject: RE: [PSES] NEMA 5-20P with IEC 60320 C13

Dave,

The question is what was the rated current on the A/C unit?  With the 
15A plug it was probably rated at 12A unless it clearly specified a 'dedicated 
circuit'.  I guess it's too long ago to go check on it.  

:>) br,  Pete

Peter E Perkins, PE
Principal Product Safety & Regulatory Affairs Consultant PO Box 23427 Tigard, 
ORe  97281-3427

503/452-1201

p.perk...@ieee.org

-Original Message-
From: Nyffenegger, Dave [mailto:dave.nyffeneg...@bhemail.com]
Sent: Wednesday, October 11, 2017 10:30 AM
To: Pete Perkins ; EMC-PSTC@LISTSERV.IEEE.ORG
Subject: RE: [PSES] NEMA 5-20P with IEC 60320 C13

Had a condo  with  a smallish through-the-wall A/C unit with NEMA 5-15P plug.  
In the room on one side of the unit was a dedicated 20A single outlet for the 
A/C unit.  In the room on the other side easily within reach of the cord was a 
standard duplex outlet on the room circuit.  Guess which one the A/C was 
plugged into?

-Dave

-Original Message-
From: Pete Perkins [mailto:0061f3f32d0c-dmarc-requ...@ieee.org]
Sent: Wednesday, October 11, 2017 1:04 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] NEMA 5-20P with IEC 60320 C13

Ralph, Ted et al,

Dunno how many times I have had this conversation with the project 
engineer who wants to use the full rated current from the duplex outlet (and 
not leave any for the other user who plugs into that outlet - which gives rise 
to the 80% rule) - except if they want to specify in the installation that the 
user must have an expensive electrician install a special dedicated outlet 
(only one plug available to the user on that CB controlled circuit); which 
gives rise to the marketing folks nixing the idea.  :>)Carry on! As you 
were doing...  

:>) br,  Pete

Peter E Perkins, PE
Principal Product Safety & Regulatory Affairs Consultant PO Box 23427 Tigard, 
ORe  97281-3427

503/452-1201

p.perk...@ieee.org

-Original Message-
From: Ralph McDiarmid [mailto:ralph.mcdiar...@schneider-electric.com]
Sent: Wednesday, October 11, 2017 9:05 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] NEMA 5-20P with IEC 60320 C13

Sounds like an example of the 125% rule for continuous (>3hr) current.  (20/16) 
 

Ralph McDiarmid
Product Compliance
Engineering
Solar Business
Schneider Electric


From: Ted Eckert [mailto:07cf6ebeab9d-dmarc-requ...@ieee.org]
Sent: Wednesday, October 11, 2017 5:50 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] NEMA 5-20P with IEC 60320 C13

NFPA 70 allows 20 A connectors to be used at 20 A under a number of 
circumstances. The derating issue only applies in certain cases. Just changing 
the rating doesn’t resolve the issue as it would eliminate already accepted 
safe use of the connectors at their full rating.

Ted Eckert
Microsoft Corporation

The opinions expressed are my own and do not necessarily reflect those of my 
employer.

From: John Woodgate [mailto:j...@woodjohn.uk]
Sent: Tuesday, October 10, 2017 11:21 PM
To: Ted Eckert ; 
mailto:EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] NEMA 5-20P with IEC 60320 C13

Yes, it could be difficult to change to respecting the rated values, so how 
about respecting the de-rated values instead? Instead of saying that you can 
only use this 20 A connector up to 16 A, call it a 16 A connector?
John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates 
https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.woodjohn.uk&data=02%7C01%7CTed.Eckert%40MICROSOFT.COM%7C6f5a4a13ae97469548f108d510703247%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C636432996434092831&sdata=vbIPUaUZRYojTmRGRu9LrQO4Emqy7f8wN1OY8mY%2BQFg%3D&reserved=0
Rayleigh, Essex UK
On 2017-10-10 21:57, Ted Eckert wrote:
The various clauses of NFPA 70 are reviewed, challenged, debated, argued and 
rewritten. I don’t think the clause in question remains because nobody has 
challenged it. Part of the issue is that the electrical infrastructure in the 
U.S. has been developed around this rule. If affects circuit breaker trip 
curves, conduit fill, wire sizes and rating and many other aspects of a 
building’s electrical system. If the rule were changed, would there be problems 
switching over? Would you have overheating in older structures where circuit 
breakers were replaced without updating wiring? Wold there be other effects of 
mixing 80% and 100% rated components? How many U.S. national standards would 
need to be updated? 
 
It i

Re: [PSES] NEMA 5-20P with IEC 60320 C13

[Kunde, Brian]

All,

So the NEC allows you to draw the full 15 amps from a 15 amp receptacle IF it 
is on a dedicated circuit. BUT if the circuit is wired to more than one 
receptacle, then the product cannot draw more than 12 amps.  What difference 
does that make? Same product, same power cord, same plug and receptacle. The 
only difference I see is with a dedicated circuit is you have no chance to 
accidently overload the branch circuit by plugging in too many loads. But why 
is this Code? You can always overload a branch circuit with multiple outlets 
even with the 80% rule.

I've always been told that the 80% rule applies to receptacles to keep them 
from overheating. BUT, if the code allows a full 15 amp load on a 15 amp 
plug/receptacle with a dedicated circuit, then it must not have anything to do 
with the cord-and-plug connection.

Many NRTL inspectors has told me that a product "cannot be rated" more than 80% 
of the "plug rating", period. Because even if we specify in our manual to use a 
"dedicated circuit", most people won't. Canada seems to be most strict with 
this rule.  They have made us change our plug and power cord to a 20 amp on 
such products. This has caused us so much grief in the past that now we follow 
the 80% rule on everything.

The Other Brian

-Original Message-
From: Pete Perkins [mailto:0061f3f32d0c-dmarc-requ...@ieee.org]
Sent: Wednesday, October 11, 2017 1:39 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] NEMA 5-20P with IEC 60320 C13

Dave,

The question is what was the rated current on the A/C unit?  With the 
15A plug it was probably rated at 12A unless it clearly specified a 'dedicated 
circuit'.  I guess it's too long ago to go check on it.

:>) br,  Pete

Peter E Perkins, PE
Principal Product Safety & Regulatory Affairs Consultant PO Box 23427 Tigard, 
ORe  97281-3427

503/452-1201

p.perk...@ieee.org

-Original Message-
From: Nyffenegger, Dave [mailto:dave.nyffeneg...@bhemail.com]
Sent: Wednesday, October 11, 2017 10:30 AM
To: Pete Perkins ; EMC-PSTC@LISTSERV.IEEE.ORG
Subject: RE: [PSES] NEMA 5-20P with IEC 60320 C13

Had a condo  with  a smallish through-the-wall A/C unit with NEMA 5-15P plug.  
In the room on one side of the unit was a dedicated 20A single outlet for the 
A/C unit.  In the room on the other side easily within reach of the cord was a 
standard duplex outlet on the room circuit.  Guess which one the A/C was 
plugged into?

-Dave

-Original Message-
From: Pete Perkins [mailto:0061f3f32d0c-dmarc-requ...@ieee.org]
Sent: Wednesday, October 11, 2017 1:04 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] NEMA 5-20P with IEC 60320 C13

Ralph, Ted et al,

Dunno how many times I have had this conversation with the project 
engineer who wants to use the full rated current from the duplex outlet (and 
not leave any for the other user who plugs into that outlet - which gives rise 
to the 80% rule) - except if they want to specify in the installation that the 
user must have an expensive electrician install a special dedicated outlet 
(only one plug available to the user on that CB controlled circuit); which 
gives rise to the marketing folks nixing the idea.  :>)Carry on! As you 
were doing...

:>) br,  Pete

Peter E Perkins, PE
Principal Product Safety & Regulatory Affairs Consultant PO Box 23427 Tigard, 
ORe  97281-3427

503/452-1201

p.perk...@ieee.org

-Original Message-
From: Ralph McDiarmid [mailto:ralph.mcdiar...@schneider-electric.com]
Sent: Wednesday, October 11, 2017 9:05 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] NEMA 5-20P with IEC 60320 C13

Sounds like an example of the 125% rule for continuous (>3hr) current.  (20/16)

Ralph McDiarmid
Product Compliance
Engineering
Solar Business
Schneider Electric


From: Ted Eckert [mailto:07cf6ebeab9d-dmarc-requ...@ieee.org]
Sent: Wednesday, October 11, 2017 5:50 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] NEMA 5-20P with IEC 60320 C13

NFPA 70 allows 20 A connectors to be used at 20 A under a number of 
circumstances. The derating issue only applies in certain cases. Just changing 
the rating doesn’t resolve the issue as it would eliminate already accepted 
safe use of the connectors at their full rating.

Ted Eckert
Microsoft Corporation

The opinions expressed are my own and do not necessarily reflect those of my 
employer.

From: John Woodgate [mailto:j...@woodjohn.uk]
Sent: Tuesday, October 10, 2017 11:21 PM
To: Ted Eckert ; 
mailto:EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] NEMA 5-20P with IEC 60320 C13

Yes, it could be difficult to change to respecting the rated values, so how 
about respecting the de-rated values instead? Instead of saying that you can 
only use this 20 A connector up to 16 A, call it a 16 A connector?
John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates 
https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.woodjohn.uk&data=0

Re: [PSES] NEMA 5-20P with IEC 60320 C13

[Nyffenegger, Dave]

Had a condo  with  a smallish through-the-wall A/C unit with NEMA 5-15P plug.  
In the room on one side of the unit was a dedicated 20A single outlet for the 
A/C unit.  In the room on the other side easily within reach of the cord was a 
standard duplex outlet on the room circuit.  Guess which one the A/C was 
plugged into?

-Dave

-Original Message-
From: Pete Perkins [mailto:0061f3f32d0c-dmarc-requ...@ieee.org] 
Sent: Wednesday, October 11, 2017 1:04 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] NEMA 5-20P with IEC 60320 C13

Ralph, Ted et al,

Dunno how many times I have had this conversation with the project 
engineer who wants to use the full rated current from the duplex outlet (and 
not leave any for the other user who plugs into that outlet - which gives rise 
to the 80% rule) - except if they want to specify in the installation that the 
user must have an expensive electrician install a special dedicated outlet 
(only one plug available to the user on that CB controlled circuit); which 
gives rise to the marketing folks nixing the idea.  :>)Carry on! As you 
were doing...  

:>) br,  Pete

Peter E Perkins, PE
Principal Product Safety & Regulatory Affairs Consultant PO Box 23427 Tigard, 
ORe  97281-3427

503/452-1201

p.perk...@ieee.org

-Original Message-
From: Ralph McDiarmid [mailto:ralph.mcdiar...@schneider-electric.com]
Sent: Wednesday, October 11, 2017 9:05 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] NEMA 5-20P with IEC 60320 C13

Sounds like an example of the 125% rule for continuous (>3hr) current.  (20/16) 
 

Ralph McDiarmid
Product Compliance
Engineering
Solar Business
Schneider Electric


From: Ted Eckert [mailto:07cf6ebeab9d-dmarc-requ...@ieee.org]
Sent: Wednesday, October 11, 2017 5:50 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] NEMA 5-20P with IEC 60320 C13

NFPA 70 allows 20 A connectors to be used at 20 A under a number of 
circumstances. The derating issue only applies in certain cases. Just changing 
the rating doesn’t resolve the issue as it would eliminate already accepted 
safe use of the connectors at their full rating.

Ted Eckert
Microsoft Corporation

The opinions expressed are my own and do not necessarily reflect those of my 
employer.

From: John Woodgate [mailto:j...@woodjohn.uk]
Sent: Tuesday, October 10, 2017 11:21 PM
To: Ted Eckert ; 
mailto:EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] NEMA 5-20P with IEC 60320 C13

Yes, it could be difficult to change to respecting the rated values, so how 
about respecting the de-rated values instead? Instead of saying that you can 
only use this 20 A connector up to 16 A, call it a 16 A connector?
John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates 
https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.woodjohn.uk&data=02%7C01%7CTed.Eckert%40MICROSOFT.COM%7C6f5a4a13ae97469548f108d510703247%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C636432996434092831&sdata=vbIPUaUZRYojTmRGRu9LrQO4Emqy7f8wN1OY8mY%2BQFg%3D&reserved=0
Rayleigh, Essex UK
On 2017-10-10 21:57, Ted Eckert wrote:
The various clauses of NFPA 70 are reviewed, challenged, debated, argued and 
rewritten. I don’t think the clause in question remains because nobody has 
challenged it. Part of the issue is that the electrical infrastructure in the 
U.S. has been developed around this rule. If affects circuit breaker trip 
curves, conduit fill, wire sizes and rating and many other aspects of a 
building’s electrical system. If the rule were changed, would there be problems 
switching over? Would you have overheating in older structures where circuit 
breakers were replaced without updating wiring? Wold there be other effects of 
mixing 80% and 100% rated components? How many U.S. national standards would 
need to be updated? 
 
It is a poor analogy, but think about switching sides that you drive on the 
road. Sweden switched on September 3, 1967. Street signs, traffic signals and 
road markings all had to be changed. Headlights had to be adjusted or re-aimed. 
For quite a while, there was a mix of left-hand and right-hand drive cars. It 
was a massive undertaking for a country with fewer people than either London or 
New York City. 
 
Changing the way branch circuits are rated in the U.S. could be done, but it 
would be an extremely complicated undertaking. The risks of a mismatch of 
circuits, circuit protection and loads would be significant for a long time. I 
suspect that by the time the technology evolved to the point where the 
requirement could be eliminated, it was too late and eliminating it would 
result in too much expense and rework.
 
Ted Eckert
Microsoft Corporation
 
The opinions expressed are my own and do not necessarily reflect those of my 
employer. 
 
From: John Woodgate [mailto:j...@woodjohn.uk]
Sent: Tuesday, October 10, 2017 12:49 PM
To: mailto:EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] NEMA 5-20P with IEC 60320 C13
 

Re: [PSES] NEMA 5-20P with IEC 60320 C13

[Pete Perkins]

Dave,

The question is what was the rated current on the A/C unit?  With the 
15A plug it was probably rated at 12A unless it clearly specified a 'dedicated 
circuit'.  I guess it's too long ago to go check on it.  

:>) br,  Pete

Peter E Perkins, PE
Principal Product Safety & Regulatory Affairs Consultant
PO Box 23427
Tigard, ORe  97281-3427

503/452-1201

p.perk...@ieee.org

-Original Message-
From: Nyffenegger, Dave [mailto:dave.nyffeneg...@bhemail.com] 
Sent: Wednesday, October 11, 2017 10:30 AM
To: Pete Perkins ; EMC-PSTC@LISTSERV.IEEE.ORG
Subject: RE: [PSES] NEMA 5-20P with IEC 60320 C13

Had a condo  with  a smallish through-the-wall A/C unit with NEMA 5-15P plug.  
In the room on one side of the unit was a dedicated 20A single outlet for the 
A/C unit.  In the room on the other side easily within reach of the cord was a 
standard duplex outlet on the room circuit.  Guess which one the A/C was 
plugged into?

-Dave

-Original Message-
From: Pete Perkins [mailto:0061f3f32d0c-dmarc-requ...@ieee.org] 
Sent: Wednesday, October 11, 2017 1:04 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] NEMA 5-20P with IEC 60320 C13

Ralph, Ted et al,

Dunno how many times I have had this conversation with the project 
engineer who wants to use the full rated current from the duplex outlet (and 
not leave any for the other user who plugs into that outlet - which gives rise 
to the 80% rule) - except if they want to specify in the installation that the 
user must have an expensive electrician install a special dedicated outlet 
(only one plug available to the user on that CB controlled circuit); which 
gives rise to the marketing folks nixing the idea.  :>)Carry on! As you 
were doing...  

:>) br,  Pete

Peter E Perkins, PE
Principal Product Safety & Regulatory Affairs Consultant PO Box 23427 Tigard, 
ORe  97281-3427

503/452-1201

p.perk...@ieee.org

-Original Message-
From: Ralph McDiarmid [mailto:ralph.mcdiar...@schneider-electric.com]
Sent: Wednesday, October 11, 2017 9:05 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] NEMA 5-20P with IEC 60320 C13

Sounds like an example of the 125% rule for continuous (>3hr) current.  (20/16) 
 

Ralph McDiarmid
Product Compliance
Engineering
Solar Business
Schneider Electric


From: Ted Eckert [mailto:07cf6ebeab9d-dmarc-requ...@ieee.org]
Sent: Wednesday, October 11, 2017 5:50 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] NEMA 5-20P with IEC 60320 C13

NFPA 70 allows 20 A connectors to be used at 20 A under a number of 
circumstances. The derating issue only applies in certain cases. Just changing 
the rating doesn’t resolve the issue as it would eliminate already accepted 
safe use of the connectors at their full rating.

Ted Eckert
Microsoft Corporation

The opinions expressed are my own and do not necessarily reflect those of my 
employer.

From: John Woodgate [mailto:j...@woodjohn.uk]
Sent: Tuesday, October 10, 2017 11:21 PM
To: Ted Eckert ; 
mailto:EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] NEMA 5-20P with IEC 60320 C13

Yes, it could be difficult to change to respecting the rated values, so how 
about respecting the de-rated values instead? Instead of saying that you can 
only use this 20 A connector up to 16 A, call it a 16 A connector?
John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates 
https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.woodjohn.uk&data=02%7C01%7CTed.Eckert%40MICROSOFT.COM%7C6f5a4a13ae97469548f108d510703247%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C636432996434092831&sdata=vbIPUaUZRYojTmRGRu9LrQO4Emqy7f8wN1OY8mY%2BQFg%3D&reserved=0
Rayleigh, Essex UK
On 2017-10-10 21:57, Ted Eckert wrote:
The various clauses of NFPA 70 are reviewed, challenged, debated, argued and 
rewritten. I don’t think the clause in question remains because nobody has 
challenged it. Part of the issue is that the electrical infrastructure in the 
U.S. has been developed around this rule. If affects circuit breaker trip 
curves, conduit fill, wire sizes and rating and many other aspects of a 
building’s electrical system. If the rule were changed, would there be problems 
switching over? Would you have overheating in older structures where circuit 
breakers were replaced without updating wiring? Wold there be other effects of 
mixing 80% and 100% rated components? How many U.S. national standards would 
need to be updated? 
 
It is a poor analogy, but think about switching sides that you drive on the 
road. Sweden switched on September 3, 1967. Street signs, traffic signals and 
road markings all had to be changed. Headlights had to be adjusted or re-aimed. 
For quite a while, there was a mix of left-hand and right-hand drive cars. It 
was a massive undertaking for a country with fewer people than either London or 
New York City. 
 
Changing the way branch circuits are rated in the U.S. could be done, but it 
would be an extreme

Re: [PSES] NEMA 5-20P with IEC 60320 C13

[Pete Perkins]

Ralph, Ted et al,

Dunno how many times I have had this conversation with the project 
engineer who wants to use the full rated current from the duplex outlet (and 
not leave any for the other user who plugs into that outlet - which gives rise 
to the 80% rule) - except if they want to specify in the installation that the 
user must have an expensive electrician install a special dedicated outlet 
(only one plug available to the user on that CB controlled circuit); which 
gives rise to the marketing folks nixing the idea.  :>)Carry on! As you 
were doing...  

:>) br,  Pete

Peter E Perkins, PE
Principal Product Safety & Regulatory Affairs Consultant
PO Box 23427
Tigard, ORe  97281-3427

503/452-1201

p.perk...@ieee.org

-Original Message-
From: Ralph McDiarmid [mailto:ralph.mcdiar...@schneider-electric.com] 
Sent: Wednesday, October 11, 2017 9:05 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] NEMA 5-20P with IEC 60320 C13

Sounds like an example of the 125% rule for continuous (>3hr) current.  (20/16) 
 

Ralph McDiarmid
Product Compliance
Engineering
Solar Business
Schneider Electric


From: Ted Eckert [mailto:07cf6ebeab9d-dmarc-requ...@ieee.org]
Sent: Wednesday, October 11, 2017 5:50 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] NEMA 5-20P with IEC 60320 C13

NFPA 70 allows 20 A connectors to be used at 20 A under a number of 
circumstances. The derating issue only applies in certain cases. Just changing 
the rating doesn’t resolve the issue as it would eliminate already accepted 
safe use of the connectors at their full rating.

Ted Eckert
Microsoft Corporation

The opinions expressed are my own and do not necessarily reflect those of my 
employer.

From: John Woodgate [mailto:j...@woodjohn.uk]
Sent: Tuesday, October 10, 2017 11:21 PM
To: Ted Eckert ; 
mailto:EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] NEMA 5-20P with IEC 60320 C13

Yes, it could be difficult to change to respecting the rated values, so how 
about respecting the de-rated values instead? Instead of saying that you can 
only use this 20 A connector up to 16 A, call it a 16 A connector?
John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates 
https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.woodjohn.uk&data=02%7C01%7CTed.Eckert%40MICROSOFT.COM%7C6f5a4a13ae97469548f108d510703247%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C636432996434092831&sdata=vbIPUaUZRYojTmRGRu9LrQO4Emqy7f8wN1OY8mY%2BQFg%3D&reserved=0
Rayleigh, Essex UK
On 2017-10-10 21:57, Ted Eckert wrote:
The various clauses of NFPA 70 are reviewed, challenged, debated, argued and 
rewritten. I don’t think the clause in question remains because nobody has 
challenged it. Part of the issue is that the electrical infrastructure in the 
U.S. has been developed around this rule. If affects circuit breaker trip 
curves, conduit fill, wire sizes and rating and many other aspects of a 
building’s electrical system. If the rule were changed, would there be problems 
switching over? Would you have overheating in older structures where circuit 
breakers were replaced without updating wiring? Wold there be other effects of 
mixing 80% and 100% rated components? How many U.S. national standards would 
need to be updated? 
 
It is a poor analogy, but think about switching sides that you drive on the 
road. Sweden switched on September 3, 1967. Street signs, traffic signals and 
road markings all had to be changed. Headlights had to be adjusted or re-aimed. 
For quite a while, there was a mix of left-hand and right-hand drive cars. It 
was a massive undertaking for a country with fewer people than either London or 
New York City. 
 
Changing the way branch circuits are rated in the U.S. could be done, but it 
would be an extremely complicated undertaking. The risks of a mismatch of 
circuits, circuit protection and loads would be significant for a long time. I 
suspect that by the time the technology evolved to the point where the 
requirement could be eliminated, it was too late and eliminating it would 
result in too much expense and rework.
 
Ted Eckert
Microsoft Corporation
 
The opinions expressed are my own and do not necessarily reflect those of my 
employer. 
 
From: John Woodgate [mailto:j...@woodjohn.uk]
Sent: Tuesday, October 10, 2017 12:49 PM
To: mailto:EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] NEMA 5-20P with IEC 60320 C13
 
Well, yes, because the IEC tends to believe that rated values are realistic and 
do not need to be adjusted downwards. I suspect that at some point in the 
distant past (maybe even nearly 100 years ago), some connectors in wide use 
were found to overheat at rated current, so the 'derating rule' was brought in, 
and no-one has challenged it since.
John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates 
https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.woodjohn.uk&data=02%7C01%7Cted.eckert%40microsoft.com%7Cb9a5abba70d24e2f

Re: [PSES] IEC 61000-3-2 Confusion

[John Woodgate]

61000-3-2, -3, -11  and -12 do not have to be cited in the Generics; 
they apply independently. 61000-3-4 assumes a dedicated MV/LV 
transformer, but the product is only 3 kW, so one can't assume that.


John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates www.woodjohn.uk
Rayleigh, Essex UK

On 2017-10-11 17:26, Ralph McDiarmid wrote:

I wonder if your customer's triac equipment falls under the EN61000-6-4 (EMC) 
Emission standard for
industrial environments?   I didn't see 61000-3-2 called out in that generic 
standard.

Ralph McDiarmid
Product Compliance
Engineering
Solar Business
Schneider Electric


From: James Pawson (U3C) [mailto:ja...@unit3compliance.co.uk]
Sent: Wednesday, October 11, 2017 9:08 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] IEC 61000-3-2 Confusion

Hello John,

It uses phase angle control hence the concern about the harmonics generated.
Manufacturer specs are single phase, 230V nominal, 3kW.
Typically used at less than a 15% duty cycle, often less, in an industrial 
environment or powered from a generator.

My *feeling* is that should be classified as professional equipment and 
exempted under Clause 7 but the IEV has 0 search for feelings.

Thanks for your help
James


From: John Woodgate [mailto:j...@woodjohn.uk]
Sent: 11 October 2017 16:49
To: mailto:EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] IEC 61000-3-2 Confusion

I agree that there appears to be a need for clarification, and I will take that 
up with the committee responsible. But for your particular case, what is 
critical is the nature of the 'triac control'. Is it phase-angle control, or 
'burst firing' or something else?
John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates http://www.woodjohn.uk
Rayleigh, Essex UK
On 2017-10-11 15:01, James Pawson (U3C) wrote:
Hi folks,
  
I apologise as I seem to be all take and not much give on this forum at the moment; I'm trying to do a lot of learning very quickly. Someone ask a question about HDMI so that I can feel useful!
  
Today's question is what appears to be a contradiction in IEC 61000-3-2:2014.
  
. The customers equipment is a triac controlled high-power PSU for welding plastic parts together using resistance heater coils

. Power is over 1kW and the customer is suggesting that it is "professional equipment" 
which, according to Clause 7, means that harmonic "limits are not specified in this 
standard"
. Flowchart in Clause 7 says that Clause 6.1 for allowed control methods still 
applies even to equipment with no limits
. Clause 6.1 says symmetrical control methods which produce large low order 
harmonics (arguably this applies to triac control) that are used to power 
heating elements (applicable) provided that either input power is less than 
200W (it isn't) or the harmonic limits of Table 3 apply
. Clause 6.1 also says that symmetrical control for professional equipment is OK provided 
one of the "above conditions" is fulfilled (which it is, see previous bullet)
  
So we've gone from Clause 7 saying no limits apply to Clause 6 saying that Class D equipment limits apply.

However the flowchart in Clause 7 suggests that just by being exempt from 
Clause 7 limits means it automatically conforms to 61000-3-2
  
I feel like I'm going in circles. Does anyone have any insight that might help?
  
Much appreciated,

James
  
  
-


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Re: [PSES] IEC 61000-3-2 Confusion

[Ralph McDiarmid]

I wonder if your customer's triac equipment falls under the EN61000-6-4 (EMC) 
Emission standard for
industrial environments?   I didn't see 61000-3-2 called out in that generic 
standard.

Ralph McDiarmid
Product Compliance
Engineering
Solar Business
Schneider Electric


From: James Pawson (U3C) [mailto:ja...@unit3compliance.co.uk] 
Sent: Wednesday, October 11, 2017 9:08 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] IEC 61000-3-2 Confusion

Hello John,

It uses phase angle control hence the concern about the harmonics generated.
Manufacturer specs are single phase, 230V nominal, 3kW.
Typically used at less than a 15% duty cycle, often less, in an industrial 
environment or powered from a generator.

My *feeling* is that should be classified as professional equipment and 
exempted under Clause 7 but the IEV has 0 search for feelings.

Thanks for your help
James


From: John Woodgate [mailto:j...@woodjohn.uk] 
Sent: 11 October 2017 16:49
To: mailto:EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] IEC 61000-3-2 Confusion

I agree that there appears to be a need for clarification, and I will take that 
up with the committee responsible. But for your particular case, what is 
critical is the nature of the 'triac control'. Is it phase-angle control, or 
'burst firing' or something else?
John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates http://www.woodjohn.uk
Rayleigh, Essex UK
On 2017-10-11 15:01, James Pawson (U3C) wrote:
Hi folks,
 
I apologise as I seem to be all take and not much give on this forum at the 
moment; I'm trying to do a lot of learning very quickly. Someone ask a question 
about HDMI so that I can feel useful!
 
Today's question is what appears to be a contradiction in IEC 61000-3-2:2014.
 
. The customers equipment is a triac controlled high-power PSU for welding 
plastic parts together using resistance heater coils
. Power is over 1kW and the customer is suggesting that it is "professional 
equipment" which, according to Clause 7, means that harmonic "limits are not 
specified in this standard"
. Flowchart in Clause 7 says that Clause 6.1 for allowed control methods still 
applies even to equipment with no limits
. Clause 6.1 says symmetrical control methods which produce large low order 
harmonics (arguably this applies to triac control) that are used to power 
heating elements (applicable) provided that either input power is less than 
200W (it isn't) or the harmonic limits of Table 3 apply
. Clause 6.1 also says that symmetrical control for professional equipment is 
OK provided one of the "above conditions" is fulfilled (which it is, see 
previous bullet)
 
So we've gone from Clause 7 saying no limits apply to Clause 6 saying that 
Class D equipment limits apply.
However the flowchart in Clause 7 suggests that just by being exempt from 
Clause 7 limits means it automatically conforms to 61000-3-2
 
I feel like I'm going in circles. Does anyone have any insight that might help?
 
Much appreciated,
James
 
 
-

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Re: [PSES] IEC 61000-3-2 Confusion

[John Woodgate]

If there is only a very remote chance of the product being connected to 
*public* LV mains supplies (as opposed to industrial supplies from a 
dedicated MV/LV transformer), 61000-3-2 doesn't apply. Does it meet the 
Class A limits?  I agree that it's 'professional equipment', but, as you 
see, the standard is not totally clear in this context. I will follow up 
with the IEC committee. It may take a few days to get an answer.


John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates www.woodjohn.uk
Rayleigh, Essex UK

On 2017-10-11 17:08, James Pawson (U3C) wrote:


Hello John,

It uses phase angle control hence the concern about the harmonics 
generated.


Manufacturer specs are single phase, 230V nominal, 3kW.

Typically used at less than a 15% duty cycle, often less, in an 
industrial environment or powered from a generator.


My *feeling* is that should be classified as professional equipment 
and exempted under Clause 7 but the IEV has 0 search for feelings.


Thanks for your help

James

*From:*John Woodgate [mailto:j...@woodjohn.uk]
*Sent:* 11 October 2017 16:49
*To:* EMC-PSTC@LISTSERV.IEEE.ORG
*Subject:* Re: [PSES] IEC 61000-3-2 Confusion

I agree that there appears to be a need for clarification, and I will 
take that up with the committee responsible. But for your particular 
case, what is critical is the nature of the 'triac control'. Is it 
phase-angle control, or 'burst firing' or something else?


John Woodgate OOO-Own Opinions Only
J M Woodgate and Associateswww.woodjohn.uk 
Rayleigh, Essex UK

On 2017-10-11 15:01, James Pawson (U3C) wrote:

Hi folks,

I apologise as I seem to be all take and not much give on this
forum at the moment; I’m trying to do a lot of learning very
quickly. Someone ask a question about HDMI so that I can feel useful!

Today’s question is what appears to be a contradiction in IEC
61000-3-2:2014.

  * The customers equipment is a triac controlled high-power PSU
for welding plastic parts together using resistance heater coils
  * Power is over 1kW and the customer is suggesting that it is
“professional equipment” which, according to Clause 7, means
that harmonic “limits are not specified in this standard”
  * Flowchart in Clause 7 says that Clause 6.1 for allowed control
methods still applies even to equipment with no limits
  * Clause 6.1 says symmetrical control methods which produce
large low order harmonics (arguably this applies to triac
control) that are used to power heating elements (applicable)
provided that either input power is less than 200W (it isn’t)
or the harmonic limits of Table 3 apply
  * Clause 6.1 also says that symmetrical control for professional
equipment is OK provided one of the “above conditions” is
fulfilled (which it is, see previous bullet)

So we’ve gone from Clause 7 saying no limits apply to Clause 6
saying that Class D equipment limits apply.

However the flowchart in Clause 7 suggests that just by being
exempt from Clause 7 limits means it automatically conforms to
61000-3-2

I feel like I’m going in circles. Does anyone have any insight
that might help?

Much appreciated,

James

-


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e-mail to mailto:emc-p...@ieee.org>>

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Re: [PSES] IEC 61000-3-2 Confusion

[James Pawson (U3C)]

Hello John,

 

It uses phase angle control hence the concern about the harmonics generated.

Manufacturer specs are single phase, 230V nominal, 3kW.

Typically used at less than a 15% duty cycle, often less, in an industrial
environment or powered from a generator.

 

My *feeling* is that should be classified as professional equipment and
exempted under Clause 7 but the IEV has 0 search for feelings.

 

Thanks for your help

James

 

 

From: John Woodgate [mailto:j...@woodjohn.uk] 
Sent: 11 October 2017 16:49
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] IEC 61000-3-2 Confusion

 

I agree that there appears to be a need for clarification, and I will take
that up with the committee responsible. But for your particular case, what
is critical is the nature of the 'triac control'. Is it phase-angle control,
or 'burst firing' or something else?

John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates www.woodjohn.uk  
Rayleigh, Essex UK

On 2017-10-11 15:01, James Pawson (U3C) wrote:

Hi folks,

 

I apologise as I seem to be all take and not much give on this forum at the
moment; I'm trying to do a lot of learning very quickly. Someone ask a
question about HDMI so that I can feel useful!

 

Today's question is what appears to be a contradiction in IEC
61000-3-2:2014.

 

*   The customers equipment is a triac controlled high-power PSU for
welding plastic parts together using resistance heater coils
*   Power is over 1kW and the customer is suggesting that it is
"professional equipment" which, according to Clause 7, means that harmonic
"limits are not specified in this standard"
*   Flowchart in Clause 7 says that Clause 6.1 for allowed control
methods still applies even to equipment with no limits
*   Clause 6.1 says symmetrical control methods which produce large low
order harmonics (arguably this applies to triac control) that are used to
power heating elements (applicable) provided that either input power is less
than 200W (it isn't) or the harmonic limits of Table 3 apply
*   Clause 6.1 also says that symmetrical control for professional
equipment is OK provided one of the "above conditions" is fulfilled (which
it is, see previous bullet)

 

So we've gone from Clause 7 saying no limits apply to Clause 6 saying that
Class D equipment limits apply.

However the flowchart in Clause 7 suggests that just by being exempt from
Clause 7 limits means it automatically conforms to 61000-3-2

 

I feel like I'm going in circles. Does anyone have any insight that might
help?

 

Much appreciated,

James

 

 

-


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discussion list. To post a message to the list, send your e-mail to
mailto:emc-p...@ieee.org> >

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Jim Bacher mailto:j.bac...@ieee.org> >
David Heald mailto:dhe...@gmail.com> > 

 

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Re: [PSES] NEMA 5-20P with IEC 60320 C13

[Ralph McDiarmid]

Sounds like an example of the 125% rule for continuous (>3hr) current.  (20/16) 
 

Ralph McDiarmid
Product Compliance
Engineering
Solar Business
Schneider Electric


From: Ted Eckert [mailto:07cf6ebeab9d-dmarc-requ...@ieee.org] 
Sent: Wednesday, October 11, 2017 5:50 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] NEMA 5-20P with IEC 60320 C13

NFPA 70 allows 20 A connectors to be used at 20 A under a number of 
circumstances. The derating issue only applies in certain cases. Just changing 
the rating doesn’t resolve the issue as it would eliminate already accepted 
safe use of the connectors at their full rating.

Ted Eckert
Microsoft Corporation

The opinions expressed are my own and do not necessarily reflect those of my 
employer.

From: John Woodgate [mailto:j...@woodjohn.uk] 
Sent: Tuesday, October 10, 2017 11:21 PM
To: Ted Eckert ; 
mailto:EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] NEMA 5-20P with IEC 60320 C13

Yes, it could be difficult to change to respecting the rated values, so how 
about respecting the de-rated values instead? Instead of saying that you can 
only use this 20 A connector up to 16 A, call it a 16 A connector?
John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates 
https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.woodjohn.uk&data=02%7C01%7CTed.Eckert%40MICROSOFT.COM%7C6f5a4a13ae97469548f108d510703247%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C636432996434092831&sdata=vbIPUaUZRYojTmRGRu9LrQO4Emqy7f8wN1OY8mY%2BQFg%3D&reserved=0
Rayleigh, Essex UK
On 2017-10-10 21:57, Ted Eckert wrote:
The various clauses of NFPA 70 are reviewed, challenged, debated, argued and 
rewritten. I don’t think the clause in question remains because nobody has 
challenged it. Part of the issue is that the electrical infrastructure in the 
U.S. has been developed around this rule. If affects circuit breaker trip 
curves, conduit fill, wire sizes and rating and many other aspects of a 
building’s electrical system. If the rule were changed, would there be problems 
switching over? Would you have overheating in older structures where circuit 
breakers were replaced without updating wiring? Wold there be other effects of 
mixing 80% and 100% rated components? How many U.S. national standards would 
need to be updated? 
 
It is a poor analogy, but think about switching sides that you drive on the 
road. Sweden switched on September 3, 1967. Street signs, traffic signals and 
road markings all had to be changed. Headlights had to be adjusted or re-aimed. 
For quite a while, there was a mix of left-hand and right-hand drive cars. It 
was a massive undertaking for a country with fewer people than either London or 
New York City. 
 
Changing the way branch circuits are rated in the U.S. could be done, but it 
would be an extremely complicated undertaking. The risks of a mismatch of 
circuits, circuit protection and loads would be significant for a long time. I 
suspect that by the time the technology evolved to the point where the 
requirement could be eliminated, it was too late and eliminating it would 
result in too much expense and rework.
 
Ted Eckert
Microsoft Corporation
 
The opinions expressed are my own and do not necessarily reflect those of my 
employer. 
 
From: John Woodgate [mailto:j...@woodjohn.uk] 
Sent: Tuesday, October 10, 2017 12:49 PM
To: mailto:EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] NEMA 5-20P with IEC 60320 C13
 
Well, yes, because the IEC tends to believe that rated values are realistic and 
do not need to be adjusted downwards. I suspect that at some point in the 
distant past (maybe even nearly 100 years ago), some connectors in wide use 
were found to overheat at rated current, so the 'derating rule' was brought in, 
and no-one has challenged it since.
John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates 
https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.woodjohn.uk&data=02%7C01%7Cted.eckert%40microsoft.com%7Cb9a5abba70d24e2f093e08d51018031b%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C636432617679408094&sdata=jNpj%2FFhCHx9ir37o7Xf5GxovOe2h0nU9FIZnbo5mItE%3D&reserved=0
Rayleigh, Essex UK
On 2017-10-10 20:12, Ralph McDiarmid wrote:
The NEC (NFPA 70) talks about “continuous currents” and when to apply the 
all-too-familiar 125% rule.  Canadian Electric Code (CSA part I) has same 
requirement.  The IEC seems to have avoided it.
 
Ralph McDiarmid
Product Compliance
Engineering
Solar Business
Schneider Electric
D  604-422-2622
 
From: Kunde, Brian [mailto:brian_ku...@lecotc.com] 
Sent: Monday, October 09, 2017 8:31 AM
To: mailto:EMC-PSTC@LISTSERV.IEEE.ORG
Subject: [PSES] NEMA 5-20P with IEC 60320 C13
 
It is my understanding that according to the US National Electric Code, 15 amp 
receptacle are derated to 12 amps max., and 20 amp receptacles are derated to 
16 amps. 
 
IEC 60320 C13 connectors are rated 15 amps in North America. Do I derate them 
as well or can I draw 15 amps cont

Re: [PSES] IEC 61000-3-2 Confusion

[John Woodgate]

I should also have asked what the rated power actually is, and whether 
it's 1-phase or 3-phase?


John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates www.woodjohn.uk
Rayleigh, Essex UK

On 2017-10-11 16:54, John Woodgate wrote:


True, but it's a cumbersome procedure and is not clearly enough 
indicated. I will try to get an improvement.


John Woodgate OOO-Own Opinions Only
J M Woodgate and Associateswww.woodjohn.uk
Rayleigh, Essex UK
On 2017-10-11 15:59, Scott Aldous wrote:

Hi James,

The flowchart in Clause 7 in the version of the standard that I have 
access to sends you to Clause 4 for professional equipment that uses 
techniques not allowed by 6.1. The second paragraph of Clause 4 
addresses professional equipment that does not comply with the 
requirements of the standard, mentioning that the instruction manual 
must indicate to ask the supply utility  for permission to connect 
and that additional recommendations can be found in IEC/TR 61000-3-4 
or IEC 61000-3-12.


On Wed, Oct 11, 2017 at 7:01 AM, James Pawson (U3C) 
mailto:ja...@unit3compliance.co.uk>> wrote:


Hi folks,

I apologise as I seem to be all take and not much give on this
forum at the moment; I’m trying to do a lot of learning very
quickly. Someone ask a question about HDMI so that I can feel useful!

Today’s question is what appears to be a contradiction in IEC
61000-3-2:2014.

  * The customers equipment is a triac controlled high-power PSU
for welding plastic parts together using resistance heater coils
  * Power is over 1kW and the customer is suggesting that it is
“professional equipment” which, according to Clause 7, means
that harmonic “limits are not specified in this standard”
  * Flowchart in Clause 7 says that Clause 6.1 for allowed
control methods still applies even to equipment with no limits
  * Clause 6.1 says symmetrical control methods which produce
large low order harmonics (arguably this applies to triac
control) that are used to power heating elements (applicable)
provided that either input power is less than 200W (it isn’t)
or the harmonic limits of Table 3 apply
  * Clause 6.1 also says that symmetrical control for
professional equipment is OK provided one of the “above
conditions” is fulfilled (which it is, see previous bullet)

So we’ve gone from Clause 7 saying no limits apply to Clause 6
saying that Class D equipment limits apply.

However the flowchart in Clause 7 suggests that just by being
exempt from Clause 7 limits means it automatically conforms to
61000-3-2

I feel like I’m going in circles. Does anyone have any insight
that might help?

Much appreciated,

James

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--
Scott Aldous | Regulatory Compliance Program 
Manager |scottald...@google.com 
 | 650-253-1994


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Re: [PSES] IEC 61000-3-2 Confusion

[John Woodgate]

True, but it's a cumbersome procedure and is not clearly enough 
indicated. I will try to get an improvement.


John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates www.woodjohn.uk
Rayleigh, Essex UK

On 2017-10-11 15:59, Scott Aldous wrote:

Hi James,

The flowchart in Clause 7 in the version of the standard that I have 
access to sends you to Clause 4 for professional equipment that uses 
techniques not allowed by 6.1. The second paragraph of Clause 4 
addresses professional equipment that does not comply with the 
requirements of the standard, mentioning that the instruction manual 
must indicate to ask the supply utility  for permission to connect and 
that additional recommendations can be found in IEC/TR 61000-3-4 or 
IEC 61000-3-12.


On Wed, Oct 11, 2017 at 7:01 AM, James Pawson (U3C) 
mailto:ja...@unit3compliance.co.uk>> wrote:


Hi folks,

I apologise as I seem to be all take and not much give on this
forum at the moment; I’m trying to do a lot of learning very
quickly. Someone ask a question about HDMI so that I can feel useful!

Today’s question is what appears to be a contradiction in IEC
61000-3-2:2014.

  * The customers equipment is a triac controlled high-power PSU
for welding plastic parts together using resistance heater coils
  * Power is over 1kW and the customer is suggesting that it is
“professional equipment” which, according to Clause 7, means
that harmonic “limits are not specified in this standard”
  * Flowchart in Clause 7 says that Clause 6.1 for allowed control
methods still applies even to equipment with no limits
  * Clause 6.1 says symmetrical control methods which produce
large low order harmonics (arguably this applies to triac
control) that are used to power heating elements (applicable)
provided that either input power is less than 200W (it isn’t)
or the harmonic limits of Table 3 apply
  * Clause 6.1 also says that symmetrical control for professional
equipment is OK provided one of the “above conditions” is
fulfilled (which it is, see previous bullet)

So we’ve gone from Clause 7 saying no limits apply to Clause 6
saying that Class D equipment limits apply.

However the flowchart in Clause 7 suggests that just by being
exempt from Clause 7 limits means it automatically conforms to
61000-3-2

I feel like I’m going in circles. Does anyone have any insight
that might help?

Much appreciated,

James

-


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e-mail to >

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site at http://product-compliance.oc.ieee.org/
 can be used for graphics
(in well-used formats), large files, etc.

Website: http://www.ieee-pses.org/
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Jim Bacher >
David Heald >




--
Scott Aldous | Regulatory Compliance Program 
Manager |scottald...@google.com 
 | 650-253-1994


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This mes

Re: [PSES] IEC 61000-3-2 Confusion

[John Woodgate]

I agree that there appears to be a need for clarification, and I will 
take that up with the committee responsible. But for your particular 
case, what is critical is the nature of the 'triac control'. Is it 
phase-angle control, or 'burst firing' or something else?


John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates www.woodjohn.uk
Rayleigh, Essex UK

On 2017-10-11 15:01, James Pawson (U3C) wrote:


Hi folks,

I apologise as I seem to be all take and not much give on this forum 
at the moment; I’m trying to do a lot of learning very quickly. 
Someone ask a question about HDMI so that I can feel useful!


Today’s question is what appears to be a contradiction in IEC 
61000-3-2:2014.


  * The customers equipment is a triac controlled high-power PSU for
welding plastic parts together using resistance heater coils
  * Power is over 1kW and the customer is suggesting that it is
“professional equipment” which, according to Clause 7, means that
harmonic “limits are not specified in this standard”
  * Flowchart in Clause 7 says that Clause 6.1 for allowed control
methods still applies even to equipment with no limits
  * Clause 6.1 says symmetrical control methods which produce large
low order harmonics (arguably this applies to triac control) that
are used to power heating elements (applicable) provided that
either input power is less than 200W (it isn’t) or the harmonic
limits of Table 3 apply
  * Clause 6.1 also says that symmetrical control for professional
equipment is OK provided one of the “above conditions” is
fulfilled (which it is, see previous bullet)

So we’ve gone from Clause 7 saying no limits apply to Clause 6 saying 
that Class D equipment limits apply.


However the flowchart in Clause 7 suggests that just by being exempt 
from Clause 7 limits means it automatically conforms to 61000-3-2


I feel like I’m going in circles. Does anyone have any insight that 
might help?


Much appreciated,

James

-


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emc-pstc discussion list. To post a message to the list, send your 
e-mail to mailto:emc-p...@ieee.org>>


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http://www.ieee-pses.org/emc-pstc.html


Attachments are not permitted but the IEEE PSES Online Communities 
site at http://product-compliance.oc.ieee.org/ can be used for 
graphics (in well-used formats), large files, etc.


Website: http://www.ieee-pses.org/
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Scott Douglas mailto:sdoug...@ieee.org>>
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David Heald mailto:dhe...@gmail.com>>




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This message is from the IEEE Product Safety Engineering Society emc-pstc discussion 
list. To post a message to the list, send your e-mail to 

All emc-pstc postings are archived and searchable on the web at:
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Jim Bacher:  
David Heald: 

Re: [PSES] IEC 61000-3-2 Confusion

[James Pawson (U3C)]

Hi Scott, thanks for your input.

 

I agree with you, but as far as I can tell the equipment does comply with the 
techniques allowed in 6.1.

 

Then it gets passed down the chart to the “Belongs to exceptions of Clause 7…” 
box where it is exempted and deemed to conform without ever having tested to 
the limits applicable from Clause 6.1.

 

Very confusing. Which has priority, the flowchart or clause 6.1?

 

All thoughts appreciated

James

 

 

 

From: Scott Aldous [mailto:0220f70c299a-dmarc-requ...@ieee.org] 
Sent: 11 October 2017 16:00
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] IEC 61000-3-2 Confusion

 

Hi James,

 

The flowchart in Clause 7 in the version of the standard that I have access to 
sends you to Clause 4 for professional equipment that uses techniques not 
allowed by 6.1. The second paragraph of Clause 4 addresses professional 
equipment that does not comply with the requirements of the standard, 
mentioning that the instruction manual must indicate to ask the supply utility  
for permission to connect and that additional recommendations can be found in 
IEC/TR 61000-3-4 or IEC 61000-3-12.

 

On Wed, Oct 11, 2017 at 7:01 AM, James Pawson (U3C) 
mailto:ja...@unit3compliance.co.uk> > wrote:

Hi folks,

 

I apologise as I seem to be all take and not much give on this forum at the 
moment; I’m trying to do a lot of learning very quickly. Someone ask a question 
about HDMI so that I can feel useful!

 

Today’s question is what appears to be a contradiction in IEC 61000-3-2:2014.

 

*   The customers equipment is a triac controlled high-power PSU for 
welding plastic parts together using resistance heater coils
*   Power is over 1kW and the customer is suggesting that it is 
“professional equipment” which, according to Clause 7, means that harmonic 
“limits are not specified in this standard”
*   Flowchart in Clause 7 says that Clause 6.1 for allowed control methods 
still applies even to equipment with no limits
*   Clause 6.1 says symmetrical control methods which produce large low 
order harmonics (arguably this applies to triac control) that are used to power 
heating elements (applicable) provided that either input power is less than 
200W (it isn’t) or the harmonic limits of Table 3 apply
*   Clause 6.1 also says that symmetrical control for professional 
equipment is OK provided one of the “above conditions” is fulfilled (which it 
is, see previous bullet)

 

So we’ve gone from Clause 7 saying no limits apply to Clause 6 saying that 
Class D equipment limits apply.

However the flowchart in Clause 7 suggests that just by being exempt from 
Clause 7 limits means it automatically conforms to 61000-3-2

 

I feel like I’m going in circles. Does anyone have any insight that might help?

 

Much appreciated,

James

 

 

-


This message is from the IEEE Product Safety Engineering Society emc-pstc 
discussion list. To post a message to the list, send your e-mail to 
 >

All emc-pstc postings are archived and searchable on the web at: 
http://www.ieee-pses.org/emc-pstc.html

Attachments are not permitted but the IEEE PSES Online Communities site at 
http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used 
formats), large files, etc.

Website: http://www.ieee-pses.org/
Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) 
 
List rules: http://www.ieee-pses.org/listrules.html 

For help, send mail to the list administrators:
Scott Douglas  >
Mike Cantwell  > 

For policy questions, send mail to:
Jim Bacher  >
David Heald  > 





 

-- 

Scott Aldous | Regulatory Compliance Program Manager | scottald...@google.com 
  | 650-253-1994

 

-


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discussion list. To post a message to the list, send your e-mail to 
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For policy questions, send mail to:
Jim Bacher mailto:j.bac...

Re: [PSES] IEC 61000-3-2 Confusion

[Scott Aldous]

Hi James,

The flowchart in Clause 7 in the version of the standard that I have access
to sends you to Clause 4 for professional equipment that uses techniques
not allowed by 6.1. The second paragraph of Clause 4 addresses professional
equipment that does not comply with the requirements of the standard,
mentioning that the instruction manual must indicate to ask the supply
utility  for permission to connect and that additional recommendations can
be found in IEC/TR 61000-3-4 or IEC 61000-3-12.

On Wed, Oct 11, 2017 at 7:01 AM, James Pawson (U3C) <
ja...@unit3compliance.co.uk> wrote:

> Hi folks,
>
>
>
> I apologise as I seem to be all take and not much give on this forum at
> the moment; I’m trying to do a lot of learning very quickly. Someone ask a
> question about HDMI so that I can feel useful!
>
>
>
> Today’s question is what appears to be a contradiction in IEC
> 61000-3-2:2014.
>
>
>
>- The customers equipment is a triac controlled high-power PSU for
>welding plastic parts together using resistance heater coils
>- Power is over 1kW and the customer is suggesting that it is
>“professional equipment” which, according to Clause 7, means that harmonic
>“limits are not specified in this standard”
>- Flowchart in Clause 7 says that Clause 6.1 for allowed control
>methods still applies even to equipment with no limits
>- Clause 6.1 says symmetrical control methods which produce large low
>order harmonics (arguably this applies to triac control) that are used to
>power heating elements (applicable) provided that either input power is
>less than 200W (it isn’t) or the harmonic limits of Table 3 apply
>- Clause 6.1 also says that symmetrical control for professional
>equipment is OK provided one of the “above conditions” is fulfilled (which
>it is, see previous bullet)
>
>
>
> So we’ve gone from Clause 7 saying no limits apply to Clause 6 saying that
> Class D equipment limits apply.
>
> However the flowchart in Clause 7 suggests that just by being exempt from
> Clause 7 limits means it automatically conforms to 61000-3-2
>
>
>
> I feel like I’m going in circles. Does anyone have any insight that might
> help?
>
>
>
> Much appreciated,
>
> James
>
>
>
>
> -
> 
>
> This message is from the IEEE Product Safety Engineering Society emc-pstc
> discussion list. To post a message to the list, send your e-mail to <
> emc-p...@ieee.org>
>
> All emc-pstc postings are archived and searchable on the web at:
> http://www.ieee-pses.org/emc-pstc.html
>
> Attachments are not permitted but the IEEE PSES Online Communities site at
> http://product-compliance.oc.ieee.org/ can be used for graphics (in
> well-used formats), large files, etc.
>
> Website: http://www.ieee-pses.org/
> Instructions: http://www.ieee-pses.org/list.html (including how to
> unsubscribe) 
> List rules: http://www.ieee-pses.org/listrules.html
>
> For help, send mail to the list administrators:
> Scott Douglas 
> Mike Cantwell 
>
> For policy questions, send mail to:
> Jim Bacher 
> David Heald 
>



-- 
Scott Aldous | Regulatory Compliance Program Manager |
scottald...@google.com | 650-253-1994

-

This message is from the IEEE Product Safety Engineering Society emc-pstc 
discussion list. To post a message to the list, send your e-mail to 


All emc-pstc postings are archived and searchable on the web at:
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Attachments are not permitted but the IEEE PSES Online Communities site at 
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[PSES] IEC 61000-3-2 Confusion

[James Pawson (U3C)]

Hi folks,

 

I apologise as I seem to be all take and not much give on this forum at the
moment; I'm trying to do a lot of learning very quickly. Someone ask a
question about HDMI so that I can feel useful!

 

Today's question is what appears to be a contradiction in IEC
61000-3-2:2014.

 

*   The customers equipment is a triac controlled high-power PSU for
welding plastic parts together using resistance heater coils
*   Power is over 1kW and the customer is suggesting that it is
"professional equipment" which, according to Clause 7, means that harmonic
"limits are not specified in this standard"
*   Flowchart in Clause 7 says that Clause 6.1 for allowed control
methods still applies even to equipment with no limits
*   Clause 6.1 says symmetrical control methods which produce large low
order harmonics (arguably this applies to triac control) that are used to
power heating elements (applicable) provided that either input power is less
than 200W (it isn't) or the harmonic limits of Table 3 apply
*   Clause 6.1 also says that symmetrical control for professional
equipment is OK provided one of the "above conditions" is fulfilled (which
it is, see previous bullet)

 

So we've gone from Clause 7 saying no limits apply to Clause 6 saying that
Class D equipment limits apply.

However the flowchart in Clause 7 suggests that just by being exempt from
Clause 7 limits means it automatically conforms to 61000-3-2

 

I feel like I'm going in circles. Does anyone have any insight that might
help?

 

Much appreciated,

James

 

 


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Re: [PSES] NEMA 5-20P with IEC 60320 C13

[Ted Eckert]

NFPA 70 allows 20 A connectors to be used at 20 A under a number of 
circumstances. The derating issue only applies in certain cases. Just changing 
the rating doesn’t resolve the issue as it would eliminate already accepted 
safe use of the connectors at their full rating.

Ted Eckert
Microsoft Corporation

The opinions expressed are my own and do not necessarily reflect those of my 
employer.

From: John Woodgate [mailto:j...@woodjohn.uk]
Sent: Tuesday, October 10, 2017 11:21 PM
To: Ted Eckert ; EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] NEMA 5-20P with IEC 60320 C13


Yes, it could be difficult to change to respecting the rated values, so how 
about respecting the de-rated values instead? Instead of saying that you can 
only use this 20 A connector up to 16 A, call it a 16 A connector?

John Woodgate OOO-Own Opinions Only

J M Woodgate and Associates 
www.woodjohn.uk

Rayleigh, Essex UK
On 2017-10-10 21:57, Ted Eckert wrote:
The various clauses of NFPA 70 are reviewed, challenged, debated, argued and 
rewritten. I don’t think the clause in question remains because nobody has 
challenged it. Part of the issue is that the electrical infrastructure in the 
U.S. has been developed around this rule. If affects circuit breaker trip 
curves, conduit fill, wire sizes and rating and many other aspects of a 
building’s electrical system. If the rule were changed, would there be problems 
switching over? Would you have overheating in older structures where circuit 
breakers were replaced without updating wiring? Wold there be other effects of 
mixing 80% and 100% rated components? How many U.S. national standards would 
need to be updated?

It is a poor analogy, but think about switching sides that you drive on the 
road. Sweden switched on September 3, 1967. Street signs, traffic signals and 
road markings all had to be changed. Headlights had to be adjusted or re-aimed. 
For quite a while, there was a mix of left-hand and right-hand drive cars. It 
was a massive undertaking for a country with fewer people than either London or 
New York City.

Changing the way branch circuits are rated in the U.S. could be done, but it 
would be an extremely complicated undertaking. The risks of a mismatch of 
circuits, circuit protection and loads would be significant for a long time. I 
suspect that by the time the technology evolved to the point where the 
requirement could be eliminated, it was too late and eliminating it would 
result in too much expense and rework.

Ted Eckert
Microsoft Corporation

The opinions expressed are my own and do not necessarily reflect those of my 
employer.

From: John Woodgate [mailto:j...@woodjohn.uk]
Sent: Tuesday, October 10, 2017 12:49 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] NEMA 5-20P with IEC 60320 C13


Well, yes, because the IEC tends to believe that rated values are realistic and 
do not need to be adjusted downwards. I suspect that at some point in the 
distant past (maybe even nearly 100 years ago), some connectors in wide use 
were found to overheat at rated current, so the 'derating rule' was brought in, 
and no-one has challenged it since.

John Woodgate OOO-Own Opinions Only

J M Woodgate and Associates 
www.woodjohn.uk

Rayleigh, Essex UK
On 2017-10-10 20:12, Ralph McDiarmid wrote:

The NEC (NFPA 70) talks about “continuous currents” and when to apply the 
all-too-familiar 125% rule.  Canadian Electric Code (CSA part I) has same 
requirement.  The IEC seems to have avoided it.



Ralph McDiarmid

Product Compliance

Engineering

Solar Business

Schneider Electric

D  604-422-2622



From: Kunde, Brian [mailto:brian_ku...@lecotc.com]

Sent: Monday, October 09, 2017 8:31 AM

To: EMC-PSTC@LISTSERV.IEEE.ORG

Subject: [PSES] NEMA 5-20P with IEC 60320 C13



It is my understanding that according to the US National Electric Code, 15 amp 
receptacle are derated to 12 amps max., and 20 amp receptacles are derated to 
16 amps.



IEC 60320 C13 connectors are rated 15 amps in North America. Do I derate them 
as well or can I draw 15 amps continuous from the C13 connector?



So here is the big question:



If I have a power cord with a NEMA-5-20P at one end, IEC 60320 C13 at the other 
end, and 14awg cordage (rated 18A), can I use/ship this power cord with a 
product rated 15 amps?



Thanks to all.

The Other Brian