RE: skinny power cords.

[Scott Lacey]

Gary,
I believe the answer is that the power cord rating of 6 or 10 amps is the
operating current, at which it will have minimum temperature rise. Under
fault conditions it will experience a rather dramatic temperature rise that
is still well below the melting temperature of the insulation. The breaker
or fuse should clear well before the cord is "cooked" to the point of
failure.

Scott Lacey

-Original Message-
From: owner-emc-p...@majordomo.ieee.org
[mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of Gary McInturff
Sent: Wednesday, October 24, 2001 12:06 PM
To: EMC-PSTC (E-mail)
Subject: skinny power cords.



Fuses and breakers etc, are provided to protect the wiring
downstream from these devices. A 15 amp breaker is allowed to have 14 AWG
wire attached and run all though my house, and terminates in a 15 amp rated
receptacle - parallel blade with ground pin.
Why then can I plug in a computer that has only a 6 or 10 amp rated
power cord? Surely, its not because the computer has supplemental fusing at
2 amps or whatever. That 2 amp fuse can't protect the wiring between it and
the 15 amp breaker in my garage from prolonged operation at 15 amps. The
breaker is completely happy running at that value so the wire just sits
there and cooks!
One would think that any  cord rated less than 15 amps, would have
to be terminated in a plug that doesn't mate with the wall outlet, much like
a 15 amp connector plugged into a 20 amp outlet.
Gary

---
This message is from the IEEE EMC Society Product Safety
Technical Committee emc-pstc discussion list.

Visit our web site at:  http://www.ewh.ieee.org/soc/emcs/pstc/

To cancel your subscription, send mail to:
 majord...@ieee.org
with the single line:
 unsubscribe emc-pstc

For help, send mail to the list administrators:
 Michael Garretson:pstc_ad...@garretson.org
 Dave Healddavehe...@mediaone.net

For policy questions, send mail to:
 Richard Nute:   ri...@ieee.org
 Jim Bacher: j.bac...@ieee.org

All emc-pstc postings are archived and searchable on the web at:
No longer online until our new server is brought online and the old
messages are imported into the new server.


---
This message is from the IEEE EMC Society Product Safety
Technical Committee emc-pstc discussion list.

Visit our web site at:  http://www.ewh.ieee.org/soc/emcs/pstc/

To cancel your subscription, send mail to:
 majord...@ieee.org
with the single line:
 unsubscribe emc-pstc

For help, send mail to the list administrators:
 Michael Garretson:pstc_ad...@garretson.org
 Dave Healddavehe...@mediaone.net

For policy questions, send mail to:
 Richard Nute:   ri...@ieee.org
 Jim Bacher: j.bac...@ieee.org

All emc-pstc postings are archived and searchable on the web at:
No longer online until our new server is brought online and the old 
messages are imported into the new server.

RE: skinny power cords.

[Jim Eichner]

I'll join the speculation...

I think it is also based on the likelihood of undetected damage to the cord
leading to a situation.  The cord lengths are limited by standards, they are
jacketed with materials designed to withstand some abuse, the condition is
easily (albeit rarely) inspected by the user, they are not supposed to be
physically attached to the wall (so no fear of damage by a metal cable clamp
for example), and so on.

The wiring in your walls, by comparison, may be more at risk, since it can't
be inspected, it is stapled to the studs, and you're always drilling or
pounding nails into walls having no idea whether or not there is wiring
behind the drywall.

Regards, 
Jim Eichner, P.Eng. 
Manager, Engineering Services 
Xantrex Technology Inc. 
Mobile Power
web: www.xantrex.com  
Any opinions expressed are those of my invisible friend, who really
exists, and frequently has gas. Honest.  




-Original Message-
From: Rich Nute [mailto:ri...@sdd.hp.com]
Sent: Wednesday, October 24, 2001 12:21 PM
To: gary.mcintu...@worldwidepackets.com
Cc: emc-p...@ieee.org
Subject: Re: skinny power cords.






Hi Gary:


Somewhere in my past, I've heard the rationale for
this conundrum.  I'm just guessing here.

Power cords and similar mains devices are sized 
based on rated load, and are not sized based on
fault-condition load.

The requirement should be that, under fault 
conditions, the device is capable of withstanding 
the fault until the overcurrent device operates 
without igniting or otherwise causing a hazard.  
It can get hot; indeed, it can exceed rated 
temperature under the fault, and it can fail, 
but it should not ignite or otherwise cause a 
hazardous condition.

A power cord is supposed to be sufficiently robust 
as to withstand the rigors of use.  There are 
different degrees of robustness according to use.
In other words, the power cord itself is not
expected to fail under normal conditions of use.  

So, the power cord should only be subject to load
faults.  Since the load is protected against 
faults, the fault-protection in the load also 
provides fault-protection for the power cord.


Best regards,
Rich






---
This message is from the IEEE EMC Society Product Safety
Technical Committee emc-pstc discussion list.

Visit our web site at:  http://www.ewh.ieee.org/soc/emcs/pstc/

To cancel your subscription, send mail to:
 majord...@ieee.org
with the single line:
 unsubscribe emc-pstc

For help, send mail to the list administrators:
 Michael Garretson:pstc_ad...@garretson.org
 Dave Healddavehe...@mediaone.net

For policy questions, send mail to:
 Richard Nute:   ri...@ieee.org
 Jim Bacher: j.bac...@ieee.org

All emc-pstc postings are archived and searchable on the web at:
No longer online until our new server is brought online and the old
messages are imported into the new server.

---
This message is from the IEEE EMC Society Product Safety
Technical Committee emc-pstc discussion list.

Visit our web site at:  http://www.ewh.ieee.org/soc/emcs/pstc/

To cancel your subscription, send mail to:
 majord...@ieee.org
with the single line:
 unsubscribe emc-pstc

For help, send mail to the list administrators:
 Michael Garretson:pstc_ad...@garretson.org
 Dave Healddavehe...@mediaone.net

For policy questions, send mail to:
 Richard Nute:   ri...@ieee.org
 Jim Bacher: j.bac...@ieee.org

All emc-pstc postings are archived and searchable on the web at:
No longer online until our new server is brought online and the old 
messages are imported into the new server.

RE: TNV Circuits

[Peter Tarver]

I received a couple of notes to advise me of an error in my
e-mail.  I was intercepted at my desk midthought and should
have not sent he e-mail until I had a chance to proof it.
When T1 is isolated from the network, it is indeed SELV.  It
is TNV-1 when not so isolate.

My apologies.

Regards,

Peter L. Tarver, PE
Product Safety Manager
Sanmina Homologation Services
peter.tar...@sanmina.com

> -Original Message-
> From: owner-emc-p...@majordomo.ieee.org
> [mailto:owner-emc-p...@majordomo.ieee.org]On
> Behalf Of Peter Tarver
> Sent: Tuesday, October 23, 2001 1:01 PM
> To: emc-p...@majordomo.ieee.org
> Cc: j...@aol.com; phopk...@ga.conklincorp.com
> Subject: RE: TNV Circuits
>
>
>
> Perry -
>
> A note of general concurrence with Joe's take on your
> circuits.  The various DSL power feeds are at this time
> treated as hazardous voltage circuits.  There is
> activity in
> IEC, TC47, to consider requirements for remote feeding
> circuits, but publication is not imminent.
>
> The UL/CSA allowance for legacy CO equipment uses
> an Outline
> of Investigation and is referred to on UL's web
> site.  There
> was a separate product category established for retrofit
> equipment intended to service the installed base
> infrastructure.  Details can be found in UL's 31JAN2001
> Bulletin to Industry.  I can forward a copy to interested
> parties.
>
> T1 circuits, if isolated from the network by a CSU or
> similar equipment in accordance with CSA or
> UL60950, will be
> TNV-1.  If span powering is present, the T1
> circuit is also
> likely to be classed as hazardous voltage (+/-130Vdc, if
> memory serves, exceeding the 120Vdc with current limiting
> Joe mentioned).
>
> Regards,
>
> Peter L. Tarver, PE
> Product Safety Manager
> Sanmina Homologation Services
> peter.tar...@sanmina.com
>
>
> From: j...@aol.com
>
> Hi Perry:
>
> If you have the reported 190 VDC span powering on your DSL
> lines, you may well be forced into the hazardous voltage
> category.  In clause 2.3.1(b), UL 60950 limits
> TNV voltages
> to 60 VDC, with voltages up to 120 VDC allowed if current
> limiting is included.  Clause 3.5.3 allows central supply
> voltages up to 80 VDC to be declared TNV-2 under certain
> circumstances.  However, voltages of 190 VDC exceed any
> definitions of TNV that I am aware of.
>
> The issue of span powering and the requisite insulation
> requirements created quite a commotion a year or two ago
> when the Second Edition of UL 1950 was about to become
> mandatory.  As written, the Second Edition would have
> rendered noncompliant a wide range of T1
> equipment that was
> widely deployed and still in production.  As I recall, the
> effort to bring this to UL's attention was led by Adtran.
>
> I seem to recall seeing a document that was worked out
> between the industry and UL to address the legacy products
> that used high voltage span powering.  I do not recall the
> details, but if it would be helpful I can look into it for
> you.  I do not know whether the agreement that was reached
> for these legacy products could be applied to your
> situation.
>
>
> Joe Randolph
>
>
>
> In a message dated 10/23/01, Perry Hopkins writes:
>
>
> My question is; by definition, shouldn't the DSL circuits
> fall under the TNV-3 and not Hazardous Voltage secondary
> circuit.  The major difference is when you are determining
> the creepage and clearance distances.  At TNV-3 you are
> allowed basic insulation between TNV-3 circuits and SELV
> circuits but at the Haz Voltage Reinforced insulation is
> required.
>
>
>
> ---
> This message is from the IEEE EMC Society Product Safety
> Technical Committee emc-pstc discussion list.
>
> Visit our web site at:
http://www.ewh.ieee.org/soc/emcs/pstc/

To cancel your subscription, send mail to:
 majord...@ieee.org
with the single line:
 unsubscribe emc-pstc

For help, send mail to the list administrators:
 Michael Garretson:pstc_ad...@garretson.org
 Dave Healddavehe...@mediaone.net

For policy questions, send mail to:
 Richard Nute:   ri...@ieee.org
 Jim Bacher: j.bac...@ieee.org

All emc-pstc postings are archived and searchable on the web
at:
No longer online until our new server is brought online
and the old messages are imported into the new server.


---
This message is from the IEEE EMC Society Product Safety
Technical Committee emc-pstc discussion list.

Visit our web site at:  http://www.ewh.ieee.org/soc/emcs/pstc/

To cancel your subscription, send mail to:
 majord...@ieee.org
with the single line:
 unsubscribe emc-pstc

For help, send mail to the list administrators:
 Michael Garretson:pstc_ad...@garretson.org
 Dave Healddavehe...@mediaone.net

For policy questions, send mail to:
 Richard Nute:   ri...@ieee.org
 Jim Bacher: j.bac...@ieee.org

All emc-pstc postings are arc

Re: EFT Failures..Update!

[Jacob Schanker]

Excuse a slightly peripheral question.

I always called it (an oily sort of brownish paper) Fish paper. I
assumed the name came from the use of fish oil to prepare it in
the 1800's. I see you are referring to it (is it the same thing?)
as fische paper. Is that what it is sold as? Was it invented by
Mr. Frederick Fische? How about a musical variant - Phish paper.

:)  Jack

Jacob Z. Schanker, P.E.
65 Crandon Way
Rochester, NY 14618
Phone: 716 442 3909
Fax: 716 442 2182
j.schan...@ieee.org


- Original Message -
From: Doug McKean 
To: EMC-PSTC Discussion Group 
Sent: Tuesday, October 23, 2001 1:14 PM
Subject: Re: EFT Failures..Update!


|
| Discussion forum problems are challenging problems to
| say the least.
|
| One thing you might want to try is to add a ground plane
| into the bottom of the case with a piece of copper plate
| or foil.  Connect the plate (or foil) to the return side of the
| power leads.  Then, if you've got some fische paper (heck
| even masking tape and several sheets of printer paper will
| work in a moment of crisis), use that to insulate the plate
| from the bottom of the board. And get the plate as close
| as possible to the bottom of the board.
|
| But to really understand what's going on, you'd probably
| have to set up something with current probes or differential
| probes to follow the effect of the pulse.
|
| Most likely what's happening is the power supply is
| acting as the source of the pulse out to your product
| (obvious but bear with me) and the power leads and
| your product are simply acting as an arm of a distorted
| dipole, i.e., low impedance source (the power supply),
| high impedance end of the arm (your product).
|
| Think for a moment of the power supply is the source
| of a dipole and the two cables from it, the ac input cord
| and the power output cord are the arms of a dipole.
|
| You're whole effort here is to disrupt that construction.
|
| Thus, it is possible that by adding ferrites to the product
| end of the power leads, you could actually enhance this
| dipole effect.  This is possibly why adding ferrites to the
| power cord to your product may not be working.  In
| other words, the ferrite increases the impedance of
| the end of the dipole arm (your product) even higher.
|
| This has been demonstrated time and again by
| Doug Smith in his many demonstrations.
|
| The effect of the plate *hopefully* disrupts this
| pseudo-dipole construction. It may, it may not.
|
| The position of ferrites can be important.  If you're
| in a real bind, then you might want to simply load up
| the entire construction with ferrites all over the place
| to see if that works.  Start removing ferrites until you
| get a minimal setup that works and go from there.
| The positions of the remaining ferrites in a working
| setup can sometimes telll you what's going on in
| a setup that's modelled after a dipole.
|
| Good luck ...
|
| Regards, Doug McKean
|
|
|
| ---
| This message is from the IEEE EMC Society Product Safety
| Technical Committee emc-pstc discussion list.
|
| Visit our web site at:  http://www.ewh.ieee.org/soc/emcs/pstc/
|
| To cancel your subscription, send mail to:
|  majord...@ieee.org
| with the single line:
|  unsubscribe emc-pstc
|
| For help, send mail to the list administrators:
|  Michael Garretson:pstc_ad...@garretson.org
|  Dave Healddavehe...@mediaone.net
|
| For policy questions, send mail to:
|  Richard Nute:   ri...@ieee.org
|  Jim Bacher: j.bac...@ieee.org
|
| All emc-pstc postings are archived and searchable on the web
at:
| No longer online until our new server is brought online and
the old messages are imported into the new server.
|


---
This message is from the IEEE EMC Society Product Safety
Technical Committee emc-pstc discussion list.

Visit our web site at:  http://www.ewh.ieee.org/soc/emcs/pstc/

To cancel your subscription, send mail to:
 majord...@ieee.org
with the single line:
 unsubscribe emc-pstc

For help, send mail to the list administrators:
 Michael Garretson:pstc_ad...@garretson.org
 Dave Healddavehe...@mediaone.net

For policy questions, send mail to:
 Richard Nute:   ri...@ieee.org
 Jim Bacher: j.bac...@ieee.org

All emc-pstc postings are archived and searchable on the web at:
No longer online until our new server is brought online and the old 
messages are imported into the new server.

Re: skinny power cords.

[Eric Monk]

Coggs. (Compliance old guys and gals)

Appliance incoming fuses fitted or not.

The other problem scenario with 'skinny power 
cords' on hand-held products is where the cord 
enters the appliance and, despite all the patent 
anti-flex cord grommets, the insulation breaks 
down with stress and the skinny power cord 
becomes a five foot length of fuse wire.

The problem is reduced in the UK where the most 
popular plug style in domestic and commercial 
applications is fitted with a HBC cartridge fuse.
PROVIDING the end user does not change the fuse 
for a higher rating. 
Three pin 13 A fused plug to BS1363.
( Oh how UL laughed at the size of our 'chunky' 
plugs but did admit they were a good idea)

British Std Certified fuse cartridges to BS1362
are available in 2, 3, 5, 7, 10 and 13 A 
ratings.  

Eric.

PS. George - you didn't get the date wrong in 
 your last mail did you ?

On 24 Oct 01 at 14:40, geor...@lexmark.com wrote:

> 
> 
> 
> Gary,
> 
> It was always my understanding that house fuses/breakers were to protect
> all the upstream stuff, e.g. service entry box, external transformers etc.
> They cannot realistically protect downstream stuff, as they have no
> knowledge of how much current is too much for a given appliance.  However,
> the house wiring should be able to carry a current up to that of the fuse
> or CB rating.
> 
> ITE manufacturers must protect their own product by the use of incoming
> fuses, CBs, etc.  A fixed line cord is part of the product.  Hence, the
> product fuse must blow before a "skinny" line cord on the product would
> melt down.  For example, suppose a device is rated to draw 2.5A (electric
> razor?) and uses a "skinny" line cord at that rating.  If an internal
> fault draws 14A, it might melt down the cord or the device, but it should
> not harm house wiring rated up to 15A.
> 
> Of course, I have been wrong before.  I think it was 1961.
> 
> George
> 
> 
> -- Forwarded by George Alspaugh/Lex/Lexmark on 10/24/2001
> 02:31 PM ---
> 
> Gary McInturff  on
> 10/24/2001 12:06:00 PM
> 
> Please respond to Gary McInturff
>   
> 
> To:   "EMC-PSTC (E-mail)" 
> cc:(bcc: George Alspaugh/Lex/Lexmark)
> Subject:  skinny power cords.
> 
> 
> 
> 
>  Fuses and breakers etc, are provided to protect the wiring
> downstream from these devices. A 15 amp breaker is allowed to have 14 AWG
> wire attached and run all though my house, and terminates in a 15 amp rated
> receptacle - parallel blade with ground pin.
>  Why then can I plug in a computer that has only a 6 or 10 amp rated
> power cord? Surely, its not because the computer has supplemental fusing at
> 2 amps or whatever. That 2 amp fuse can't protect the wiring between it and
> the 15 amp breaker in my garage from prolonged operation at 15 amps. The
> breaker is completely happy running at that value so the wire just sits
> there and cooks!
>  One would think that any  cord rated less than 15 amps, would have
> to be terminated in a plug that doesn't mate with the wall outlet, much like
> a 15 amp connector plugged into a 20 amp outlet.
>  Gary
> 
> 
> 
> 
> 
> ---
> This message is from the IEEE EMC Society Product Safety
> Technical Committee emc-pstc discussion list.
> 
> Visit our web site at:  http://www.ewh.ieee.org/soc/emcs/pstc/
> 
> To cancel your subscription, send mail to:
>  majord...@ieee.org
> with the single line:
>  unsubscribe emc-pstc
> 
> For help, send mail to the list administrators:
>  Michael Garretson:pstc_ad...@garretson.org
>  Dave Healddavehe...@mediaone.net
> 
> For policy questions, send mail to:
>  Richard Nute:   ri...@ieee.org
>  Jim Bacher: j.bac...@ieee.org
> 
> All emc-pstc postings are archived and searchable on the web at:
> No longer online until our new server is brought online and the old 
> messages are imported into the new server.
> 

*  Your best support in "TESTING" situations   *
*   INTERTest Systems UK   *
* International Product Certification  *
*ONE-STOP-SHOP for ALL testing *
*PO Box 321 - Bucks HP9 1XJ - England  *
*   ++44 (0)1494 673438  Fax 678868*
* INTERTest Systems UK is the trading name of  *
*  the test laboratory of E M Consulting Ltd.  *

---
This message is from the IEEE EMC Society Product Safety
Technical Committee emc-pstc discussion list.

Visit our web site at:  http://www.ewh.ieee.org/soc/emcs/pstc/

To cancel your subscription, send mail to:
 majord...@ieee.org
with the single line:
 unsubscribe emc-pstc

For help, send mail to the list administrators:
 Michael Garretson:pstc_ad...@garretson.org
 Dave Healddavehe...@mediaone.net

For policy questions, send mail to:
 Ri

Re: NEC Question

[Jacob Schanker]

Mike:

There is no Federal requirement for the manufacturer to have
equipment listed or NRTL approved. The requirements are set by
localities, as Richard Woods clearly points out.

I can understand that in some companies, the "powers-that-be"
have little patience with the time and expense of obtaining a
listing. The delay in hitting the market is often more costly
than the approval process itself.

I say TOUGH. They should have allowed for that in the original
project plan and schedule. There was one, wasn't there?

If you are having a problem, just ask marketing to agree to
exclude the areas that Richard enumerated from their sales areas.
If it's OK to exclude LA, etc. etc., than listing isn't needed,
legally.

But the competition may be listing, so not doing so puts you at a
disadvantage.

I have asked managers to imagine sitting on the witness stand at
a product liability trial, and trying to answer the question, why
didn't you get safety approval from an NRTL?

When the implications of shortcuts are driven home, most people
see the light. Those that don't need to stick their fingers in an
unlisted light socket.

Rant concluded, best regards,

Jack

Jacob Z. Schanker, P.E.
65 Crandon Way
Rochester, NY 14618
Phone: 716 442 3909
Fax: 716 442 2182
j.schan...@ieee.org

- Original Message -
From: 
To: 
Sent: Wednesday, October 24, 2001 12:23 PM
Subject: RE: NEC Question


|
| Mike, regardless of what the NEC says, and it is not very clear
in this
| regard, it is the state, county and city electrical codes and
other local
| regulations that apply. Many jurisdictions have deviations from
the NEC
| and/or have other regulations that require electrical equipment
sold to the
| general public be Listed. I know of the following locations:
Virginia, North
| Carolina, Los Angeles, Counties of Los Angeles and Orange, and
San
| Francisco. I have also heard but cannot confirm that other
locations include
| Oregon, Washington, New York city and Chicago.
|
| Richard Woods
| Sensormatic Electronics
|
|
| -Original Message-
| From: Mike Morrow [mailto:mi...@ucentric.com]
| Sent: Wednesday, October 24, 2001 11:52 AM
| To: EMC Society
| Subject: NEC Question
|
|
|
| Can someone point me to a section in the NEC that says a piece
of
| RESIDENTIAL computer equipment must be "listed" (NEC
definition).  Article
| 645  which requires a "listed" piece of equipment appears to
apply to a
| computer room and not a residence.
|
| Basically I've been asked where its says a piece of computer
equipment must
| listed/approved by a NRTL.  I'm ignoring the obvious liability
implications
| should someone get injured for the purposes of this question..
|
| Any help is appreciated.
|
| Mike Morrow
| Senior Compliance Engineer
| Ucentric Systems, LLC
| 978-823-8166
| mi...@ucentric.com
|
|
| ---
| This message is from the IEEE EMC Society Product Safety
| Technical Committee emc-pstc discussion list.
|
| Visit our web site at:  http://www.ewh.ieee.org/soc/emcs/pstc/
|
| To cancel your subscription, send mail to:
|  majord...@ieee.org
| with the single line:
|  unsubscribe emc-pstc
|
| For help, send mail to the list administrators:
|  Michael Garretson:pstc_ad...@garretson.org
|  Dave Healddavehe...@mediaone.net
|
| For policy questions, send mail to:
|  Richard Nute:   ri...@ieee.org
|  Jim Bacher: j.bac...@ieee.org
|
| All emc-pstc postings are archived and searchable on the web
at:
| No longer online until our new server is brought online and
the old
| messages are imported into the new server.
|
| ---
| This message is from the IEEE EMC Society Product Safety
| Technical Committee emc-pstc discussion list.
|
| Visit our web site at:  http://www.ewh.ieee.org/soc/emcs/pstc/
|
| To cancel your subscription, send mail to:
|  majord...@ieee.org
| with the single line:
|  unsubscribe emc-pstc
|
| For help, send mail to the list administrators:
|  Michael Garretson:pstc_ad...@garretson.org
|  Dave Healddavehe...@mediaone.net
|
| For policy questions, send mail to:
|  Richard Nute:   ri...@ieee.org
|  Jim Bacher: j.bac...@ieee.org
|
| All emc-pstc postings are archived and searchable on the web
at:
| No longer online until our new server is brought online and
the old messages are imported into the new server.
|


---
This message is from the IEEE EMC Society Product Safety
Technical Committee emc-pstc discussion list.

Visit our web site at:  http://www.ewh.ieee.org/soc/emcs/pstc/

To cancel your subscription, send mail to:
 majord...@ieee.org
with the single line:
 unsubscribe emc-pstc

For help, send mail to the list administrators:
 Michael Garretson:pstc_ad...@garretson.org
 Dave Healddavehe...@mediaone.net

For policy questions, s

Re: skinny power cords.

[Nick Rouse]

Hello Gary,

Sounds like your making a case
for the wider adoption of the UK
system with fused plugs rated
to protect the power cord

Nick Rouse

- Original Message -
From: "Gary McInturff" 
To: "EMC-PSTC (E-mail)" 
Sent: Wednesday, October 24, 2001 5:06 PM
Subject: skinny power cords.


>
>
> Fuses and breakers etc, are provided to protect the wiring
> downstream from these devices. A 15 amp breaker is allowed to have 14 AWG
> wire attached and run all though my house, and terminates in a 15 amp
rated
> receptacle - parallel blade with ground pin.
> Why then can I plug in a computer that has only a 6 or 10 amp rated
> power cord? Surely, its not because the computer has supplemental fusing
at
> 2 amps or whatever. That 2 amp fuse can't protect the wiring between it
and
> the 15 amp breaker in my garage from prolonged operation at 15 amps. The
> breaker is completely happy running at that value so the wire just sits
> there and cooks!
> One would think that any  cord rated less than 15 amps, would have
> to be terminated in a plug that doesn't mate with the wall outlet, much
like
> a 15 amp connector plugged into a 20 amp outlet.
> Gary
>
> ---
> This message is from the IEEE EMC Society Product Safety
> Technical Committee emc-pstc discussion list.
>
> Visit our web site at:  http://www.ewh.ieee.org/soc/emcs/pstc/
>
> To cancel your subscription, send mail to:
>  majord...@ieee.org
> with the single line:
>  unsubscribe emc-pstc
>
> For help, send mail to the list administrators:
>  Michael Garretson:pstc_ad...@garretson.org
>  Dave Healddavehe...@mediaone.net
>
> For policy questions, send mail to:
>  Richard Nute:   ri...@ieee.org
>  Jim Bacher: j.bac...@ieee.org
>
> All emc-pstc postings are archived and searchable on the web at:
> No longer online until our new server is brought online and the old
messages are imported into the new server.


---
This message is from the IEEE EMC Society Product Safety
Technical Committee emc-pstc discussion list.

Visit our web site at:  http://www.ewh.ieee.org/soc/emcs/pstc/

To cancel your subscription, send mail to:
 majord...@ieee.org
with the single line:
 unsubscribe emc-pstc

For help, send mail to the list administrators:
 Michael Garretson:pstc_ad...@garretson.org
 Dave Healddavehe...@mediaone.net

For policy questions, send mail to:
 Richard Nute:   ri...@ieee.org
 Jim Bacher: j.bac...@ieee.org

All emc-pstc postings are archived and searchable on the web at:
No longer online until our new server is brought online and the old 
messages are imported into the new server.

Re: skinny power cords.

[Rich Nute]

Hi Gary:


Somewhere in my past, I've heard the rationale for
this conundrum.  I'm just guessing here.

Power cords and similar mains devices are sized 
based on rated load, and are not sized based on
fault-condition load.

The requirement should be that, under fault 
conditions, the device is capable of withstanding 
the fault until the overcurrent device operates 
without igniting or otherwise causing a hazard.  
It can get hot; indeed, it can exceed rated 
temperature under the fault, and it can fail, 
but it should not ignite or otherwise cause a 
hazardous condition.

A power cord is supposed to be sufficiently robust 
as to withstand the rigors of use.  There are 
different degrees of robustness according to use.
In other words, the power cord itself is not
expected to fail under normal conditions of use.  

So, the power cord should only be subject to load
faults.  Since the load is protected against 
faults, the fault-protection in the load also 
provides fault-protection for the power cord.


Best regards,
Rich






---
This message is from the IEEE EMC Society Product Safety
Technical Committee emc-pstc discussion list.

Visit our web site at:  http://www.ewh.ieee.org/soc/emcs/pstc/

To cancel your subscription, send mail to:
 majord...@ieee.org
with the single line:
 unsubscribe emc-pstc

For help, send mail to the list administrators:
 Michael Garretson:pstc_ad...@garretson.org
 Dave Healddavehe...@mediaone.net

For policy questions, send mail to:
 Richard Nute:   ri...@ieee.org
 Jim Bacher: j.bac...@ieee.org

All emc-pstc postings are archived and searchable on the web at:
No longer online until our new server is brought online and the old 
messages are imported into the new server.

RE: Shrunk-die power MOSFET's and compliance

[Jim Eichner]

Well for example, I have just finished specifying what compliance re-testing
I am going to need to do on 4 different products whose power conversion
stages use IRF630's, IRF740's, IRF840's, and RFP50N06's, but the list goes
on and on.  If you are using power FET's in power electronics, chances are
they have changed or will soon.  The main manufacturers that come to mind
are IR, Fairchild/Harris, Philips, and STM-Thomson.  Not all have forced
changes to the shrunk-die version - some have agreed to keep the old style
available - and all have at least added a suffix to their markings on the
devices so you can tell if it's the new revision die or old.  In one case,
however, we received modified parts with no markings differentiating them
from the old rev parts, for almost a year with no communication from the mfr
telling us about the change.  We found out through other channels and then
contacted them.  They seem to be behaving as if fundamental changes to the
performance and specifications of the part are none of our business.

I am re-doing radiated and conducted emissions, some thermal testing, and a
bunch of functional testing and looking at waveforms on 4 different products
affected by this change.  Those are only the products I am responsible for -
as a company we're doing functional testing and possibly compliance
re-testing on many more products.

This is not a simple component substitution exercise, if your products are
or use power electronics!  I would advise everyone potentially affected to
have your procurement department look into this.

Regards, 
Jim Eichner, P.Eng. 
Manager, Engineering Services 
Xantrex Technology Inc. 
Mobile Power
web: www.xantrex.com  
Any opinions expressed are those of my invisible friend, who really
exists. Honest.



-Original Message-
From: Michael Mertinooke [mailto:mertino...@skyskan.com]
Sent: Wednesday, October 24, 2001 6:45 AM
To: 'Jim Eichner'
Subject: RE: Shrunk-die power MOSFET's and compliance


Jim;

I suspect that a lot of us just don't have time to investigate the latest
subtleties involved in producing a new chip design sold under an
old component part number. We order by manufacturer part number
and when the order comes in we count the pieces and throw it in
the stockroom. 

If there are reliability problems, most companies take a month or
so for the news to get back from Field Service. Then the issue goes
to Manufacturing because we know the design worked perfectly for
X years, so Manufacturing must have built 'em wrong, or the PC
house had a bad batch of boards or somebody screwed up the
wave solder machine again or the stockroom was sweeping parts
off the floor and dumping them back in the bins ... or a hundred
other cockups that happen every day. By the time somebody 
finally figures out that the FETs are not performing as they should,
it could be a year after the parts first hit the receiving dock.

Instead of a general reference, perhaps you can provide a few 
part numbers? If I see such a list and my FETs are on it, then 
I sure as hell am going to look into it immediately! 

Thanks.
Mike Mertinooke

---
This message is from the IEEE EMC Society Product Safety
Technical Committee emc-pstc discussion list.

Visit our web site at:  http://www.ewh.ieee.org/soc/emcs/pstc/

To cancel your subscription, send mail to:
 majord...@ieee.org
with the single line:
 unsubscribe emc-pstc

For help, send mail to the list administrators:
 Michael Garretson:pstc_ad...@garretson.org
 Dave Healddavehe...@mediaone.net

For policy questions, send mail to:
 Richard Nute:   ri...@ieee.org
 Jim Bacher: j.bac...@ieee.org

All emc-pstc postings are archived and searchable on the web at:
No longer online until our new server is brought online and the old 
messages are imported into the new server.

RE: NEC Question

[BurchJ]

Hi Mike,

I don't know if this will help but, CFR 29 Section 1910.399 subpart S..  is 
where the NRTL'S  hang their hats on this issue.

Good Luck

Joe

Josiah P. Burch
Compliance Engineer II
Andover Controls Corporation
300 Brickstone Square
Andover,Ma 01810
(978)-470-0555  x335
(978)-470-3615  Fax

> -Original Message-
> From: Mike Morrow [SMTP:mi...@ucentric.com]
> Sent: Wednesday, October 24, 2001 11:52 AM
> To:   EMC Society
> Subject:  NEC Question
> 
> 
> Can someone point me to a section in the NEC that says a piece of
> RESIDENTIAL computer equipment must be "listed" (NEC definition).  Article
> 645  which requires a "listed" piece of equipment appears to apply to a
> computer room and not a residence.
> 
> Basically I've been asked where its says a piece of computer equipment must
> listed/approved by a NRTL.  I'm ignoring the obvious liability implications
> should someone get injured for the purposes of this question..
> 
> Any help is appreciated.
> 
> Mike Morrow
> Senior Compliance Engineer
> Ucentric Systems, LLC
> 978-823-8166
> mi...@ucentric.com
> 
> 
> ---
> This message is from the IEEE EMC Society Product Safety
> Technical Committee emc-pstc discussion list.
> 
> Visit our web site at:  http://www.ewh.ieee.org/soc/emcs/pstc/
> 
> To cancel your subscription, send mail to:
>  majord...@ieee.org
> with the single line:
>  unsubscribe emc-pstc
> 
> For help, send mail to the list administrators:
>  Michael Garretson:pstc_ad...@garretson.org
>  Dave Healddavehe...@mediaone.net
> 
> For policy questions, send mail to:
>  Richard Nute:   ri...@ieee.org
>  Jim Bacher: j.bac...@ieee.org
> 
> All emc-pstc postings are archived and searchable on the web at:
> No longer online until our new server is brought online and the old 
> messages are imported into the new server.

skinny power cords.

[georgea]

Gary,

It was always my understanding that house fuses/breakers were to protect
all the upstream stuff, e.g. service entry box, external transformers etc.
They cannot realistically protect downstream stuff, as they have no
knowledge of how much current is too much for a given appliance.  However,
the house wiring should be able to carry a current up to that of the fuse
or CB rating.

ITE manufacturers must protect their own product by the use of incoming
fuses, CBs, etc.  A fixed line cord is part of the product.  Hence, the
product fuse must blow before a "skinny" line cord on the product would
melt down.  For example, suppose a device is rated to draw 2.5A (electric
razor?) and uses a "skinny" line cord at that rating.  If an internal
fault draws 14A, it might melt down the cord or the device, but it should
not harm house wiring rated up to 15A.

Of course, I have been wrong before.  I think it was 1961.

George


-- Forwarded by George Alspaugh/Lex/Lexmark on 10/24/2001
02:31 PM ---

Gary McInturff  on
10/24/2001 12:06:00 PM

Please respond to Gary McInturff
  

To:   "EMC-PSTC (E-mail)" 
cc:(bcc: George Alspaugh/Lex/Lexmark)
Subject:  skinny power cords.




 Fuses and breakers etc, are provided to protect the wiring
downstream from these devices. A 15 amp breaker is allowed to have 14 AWG
wire attached and run all though my house, and terminates in a 15 amp rated
receptacle - parallel blade with ground pin.
 Why then can I plug in a computer that has only a 6 or 10 amp rated
power cord? Surely, its not because the computer has supplemental fusing at
2 amps or whatever. That 2 amp fuse can't protect the wiring between it and
the 15 amp breaker in my garage from prolonged operation at 15 amps. The
breaker is completely happy running at that value so the wire just sits
there and cooks!
 One would think that any  cord rated less than 15 amps, would have
to be terminated in a plug that doesn't mate with the wall outlet, much like
a 15 amp connector plugged into a 20 amp outlet.
 Gary





---
This message is from the IEEE EMC Society Product Safety
Technical Committee emc-pstc discussion list.

Visit our web site at:  http://www.ewh.ieee.org/soc/emcs/pstc/

To cancel your subscription, send mail to:
 majord...@ieee.org
with the single line:
 unsubscribe emc-pstc

For help, send mail to the list administrators:
 Michael Garretson:pstc_ad...@garretson.org
 Dave Healddavehe...@mediaone.net

For policy questions, send mail to:
 Richard Nute:   ri...@ieee.org
 Jim Bacher: j.bac...@ieee.org

All emc-pstc postings are archived and searchable on the web at:
No longer online until our new server is brought online and the old 
messages are imported into the new server.

RE: EFT Failures..Update!

[Chris Maxwell]

I agree with Paul's take. One of the "trees" in the forest is keyboards.
Do you have any keyboards attached to the DUT?  I have personally seen
an instance where EFT was coupling to a keyboard cable and causing all
sorts of wierd effects.

I thought it was our design's fault, so I tried filtering, ferrites ...
at our end of the keyboard cable.  No use.  It wasn't until I got to the
test lab that they suggested a ferrite at the keyboard end of the
cable.>> problem solved.  Apparantly the keyboard itself was being
upset and was sending garbage instructions to our unit.  The keyboard
was CE markedbut you never know.



> -Original Message-
> From: Hare, Paul [SMTP:ph...@pirus.com]
> Sent: Wednesday, October 24, 2001 11:25 AM
> To:   'alex.mcn...@ingenicofortronic.com'; emc-p...@majordomo.ieee.org
> Subject:  RE: EFT Failures..Update!
> 
> 
> Alex, make sure you investigate whether or not energy is coupling to
> other
> cables of the EUT and causing problems.  In other words, try to reduce
> the
> system (remove cables) and see if the EFT failures persist.  If you
> can't
> remove a cable due to functionality, place ferrites on it instead
> (near the
> EUT).   You may be surprised how a failure manifests itself.
> Sometimes
> you've got to back up and take a look at the forest...  :)
> 
> Good luck...
> 
> Paul Hare   e: ph...@pirus.com
> Compliance Engineer w: 978.206.9179
> Pirus Networks  f: 978.206.9199
> 43 Nagog Park   c: 508.450.0376
> Acton, MA 01720 i: www.pirus.com
> 
> 
> -Original Message-
> From: am...@westin-emission.no [mailto:am...@westin-emission.no]
> Sent: Wednesday, October 24, 2001 4:04 AM
> To: emc-p...@majordomo.ieee.org
> Subject: SV: EFT Failures..Update!
> 
> 
> 
> Alex,
> 
> What happened during the burst test ? Did the EUT break down or did
> you only
> have minor disturbances/faults during the test ?
> 
> I assume that you know that EFT/bursts usually is a performance
> criteria B
> test, which means that temporary faults are accepted during the test,
> as
> long that the EUT is self-recoverable after the test.
> 
> Amund
> 
> -Opprinnelig melding-
> Fra: owner-emc-p...@majordomo.ieee.org
> [mailto:owner-emc-p...@majordomo.ieee.org]På vegne av Alex McNeil
> Sendt: 23. oktober 2001 10:44
> Til: 'emc-p...@majordomo.ieee.org'
> Emne: EFT Failures..Update!
> 
> 
> 
> 
> Hi Group,
> 
> THANKS for your very much appreciated responses!! I was in panic
> mode!!
> 
> I thought it would be appropriate to let you know the status.
> 
> My product is a small all plastic enclosure Point if Sale (POS) Class
> III
> terminal. It has an external SMPS, Class II, no earth, supplying SELV,
> 12Vdc
> 1.5A to my product. The power supply works OK with some of our other
> products, for EMC. The problem is with my product.
> 
> I solved the problem at the test house by wrapping a few turns of the
> DC PSU
> cable through a "Large" Ferrite Clamp at the Product input (it did not
> work
> so well at the PSU I/P nor O/P). The fix cannot be considered final
> due to
> obvious reasons.
> 
> I am now at my Lab, now the serious diagnostics begin. I have been
> trying
> various "quick fixes" to no avail i.e. Caps, TVS, MOV etc.
> 
> If you have any further comments feel free to email me.
> 
> THANKS again to all those who responded with their thoughts. I can
> tell you
> they were wide and varied just as you would expect to trying to
> resolve an
> EMC problem over the NET!!
> 
> Best Regards
> alex.mcn...@ingenicofortronic.com
> 
> 
> 
> 
> 
> 
> 
> 
> >  -Original Message-
> > From:   Alex McNeil
> > Sent:   22 October 2001 11:23
> > To: emc-p...@majordomo.ieee.org
> > Subject:EFT Failures..Help!
> >
> > Hi Guys,
> >
> > I am at an EMC test centre today and tomorrow. Unfortunately, my
> product
> > failed EFT testing on the AC power port at 1KV. This is for various
> > combinations of Line, Neutral and Earth (L, N, E, LN, LE, NE and
> LNE)
> >
> > My product is Class II, no Earth. It is supplied by an external
> power
> > supply. This supplies SELV to my product. The power supply
> manufacturer
> > has stated that his power supply meets EN61000-4-4 for 2KV and has
> emailed
> > me this report to verify this.
> >
> > Has anyone got a quick solution to my problem so that I can
> implement here
> > at the EMC test house?
> >
> > Kind Regards
> > Alex McNeil
> > Principal Engineer
> > Tel: +44 (0)131 479 8375
> > Fax: +44 (0)131 479 8321
> > email: alex.mcn...@ingenicofortronic.com
> >
> 
> ---
> This message is from the IEEE EMC Society Product Safety
> Technical Committee emc-pstc discussion list.
> 
> Visit our web site at:  http://www.ewh.ieee.org/soc/emcs/pstc/
> 
> To cancel your subscription, send mail to:
>  majord...@ieee.org
> with the single line:
>  unsubscribe emc-pstc
> 
> For help, send mail to the list administrators:
>  Michael Garretson:pst

Re: skinny power cords.

[Ken Javor]

I am NOT an expert in this field so I could likely stand some educating but
the following seem to me to be common sense:

1) Household circuit breakers protect household wiring - only.  They prevent
wiring damage and fires.  There is no practical way to provide breakers for
every different kind of load.

2) I extrapolate your logic to imply that every appliance, including low
power consumers such as a clock radios, would be forced to use AWG 12 power
cords.

3) If an appliance such as a computer does have an internal fuse between
power cord and power supply such that any short in the appliance will draw
current through the fuse, why would the power cord have to be rated at any
higher ampacity than the fuse itself, other than a reasonable safety margin?
In other words, what is wrong with using a 6 or 10 Amp rated power cord with
a device fused at 2 Amps, to use your example?

--
>From: Gary McInturff 
>To: "EMC-PSTC (E-mail)" 
>Subject: skinny power cords.
>Date: Wed, Oct 24, 2001, 11:06 AM
>

>
>  Fuses and breakers etc, are provided to protect the wiring
> downstream from these devices. A 15 amp breaker is allowed to have 14 AWG
> wire attached and run all though my house, and terminates in a 15 amp rated
> receptacle - parallel blade with ground pin.
>  Why then can I plug in a computer that has only a 6 or 10 amp rated
> power cord? Surely, its not because the computer has supplemental fusing at
> 2 amps or whatever. That 2 amp fuse can't protect the wiring between it and
> the 15 amp breaker in my garage from prolonged operation at 15 amps. The
> breaker is completely happy running at that value so the wire just sits
> there and cooks!
>  One would think that any  cord rated less than 15 amps, would have
> to be terminated in a plug that doesn't mate with the wall outlet, much like
> a 15 amp connector plugged into a 20 amp outlet.
>  Gary
>
> ---
> This message is from the IEEE EMC Society Product Safety
> Technical Committee emc-pstc discussion list.
>
> Visit our web site at:  http://www.ewh.ieee.org/soc/emcs/pstc/
>
> To cancel your subscription, send mail to:
>  majord...@ieee.org
> with the single line:
>  unsubscribe emc-pstc
>
> For help, send mail to the list administrators:
>  Michael Garretson:pstc_ad...@garretson.org
>  Dave Healddavehe...@mediaone.net
>
> For policy questions, send mail to:
>  Richard Nute:   ri...@ieee.org
>  Jim Bacher: j.bac...@ieee.org
>
> All emc-pstc postings are archived and searchable on the web at:
> No longer online until our new server is brought online and the old
> messages are imported into the new server.
> 

---
This message is from the IEEE EMC Society Product Safety
Technical Committee emc-pstc discussion list.

Visit our web site at:  http://www.ewh.ieee.org/soc/emcs/pstc/

To cancel your subscription, send mail to:
 majord...@ieee.org
with the single line:
 unsubscribe emc-pstc

For help, send mail to the list administrators:
 Michael Garretson:pstc_ad...@garretson.org
 Dave Healddavehe...@mediaone.net

For policy questions, send mail to:
 Richard Nute:   ri...@ieee.org
 Jim Bacher: j.bac...@ieee.org

All emc-pstc postings are archived and searchable on the web at:
No longer online until our new server is brought online and the old 
messages are imported into the new server.

Re: Insulated Electrolytic Capacitors

[Douglas_Beckwith]

From:  Douglas Beckwith@MITEL on 10/24/2001 02:05 PM
Hi Peter,
My understanding of 60950 is that distance through insulation applies here
(0.4mm). I have never had this issue with CSA.

Regards

Doug Beckwith
Mitel Networks




Peter Merguerian  on 10/24/2001 09:38:19 AM

Please respond to Peter Merguerian 

To:   "\"EMC-PSTC (E-mail)\" <" 
cc:(bcc: Douglas Beckwith/Kan/Mitel)

Subject:  Insulated Electrolytic Capacitors




Dear All,

I have submitted an ac input to dc output switching power supply for NRTL
approval. One deviation is that the primary ac insulated capacitor is too
close to the earthed chassis and that the insulation cannot be relied to
provide the required basic insulation.

1. What is the group's opinion regarding this point? I have personally seen
many Listed/Recognized units with clearance distance less than 2.0 mm to the
earthed chassis without any additional insulation to provide the required
insulation. In fact, I am holding a switching power supply by a reputable
manufacturer with only approx. 0.7 mm between the primary and earthed
chassis. This power supply is  UL Recognized and TUV approved.

2. There is a UL Pag 156002 regarding this issue, but it seems that some
NRTL engineers are using their own judgement and approving units at their
own discretion.





This e-mail message may contain privileged or confidential information. If
you are not the intended recipient, you may not disclose, use, disseminate,
distribute, copy or rely upon this message or attachment in any way. If you
received this e-mail message in error, please return by forwarding the
message and its attachments to the sender.




PETER S. MERGUERIAN
Technical Director
I.T.L. (Product Testing) Ltd.
26 Hacharoshet St., POB 211
Or Yehuda 60251, Israel
Tel: + 972-(0)3-5339022  Fax: + 972-(0)3-5339019
Mobile: + 972-(0)54-838175






---
This message is from the IEEE EMC Society Product Safety
Technical Committee emc-pstc discussion list.

Visit our web site at:  http://www.ewh.ieee.org/soc/emcs/pstc/

To cancel your subscription, send mail to:
 majord...@ieee.org
with the single line:
 unsubscribe emc-pstc

For help, send mail to the list administrators:
 Michael Garretson:pstc_ad...@garretson.org
 Dave Healddavehe...@mediaone.net

For policy questions, send mail to:
 Richard Nute:   ri...@ieee.org
 Jim Bacher: j.bac...@ieee.org

All emc-pstc postings are archived and searchable on the web at:
No longer online until our new server is brought online and the old messages
are imported into the new server.







---
This message is from the IEEE EMC Society Product Safety
Technical Committee emc-pstc discussion list.

Visit our web site at:  http://www.ewh.ieee.org/soc/emcs/pstc/

To cancel your subscription, send mail to:
 majord...@ieee.org
with the single line:
 unsubscribe emc-pstc

For help, send mail to the list administrators:
 Michael Garretson:pstc_ad...@garretson.org
 Dave Healddavehe...@mediaone.net

For policy questions, send mail to:
 Richard Nute:   ri...@ieee.org
 Jim Bacher: j.bac...@ieee.org

All emc-pstc postings are archived and searchable on the web at:
No longer online until our new server is brought online and the old 
messages are imported into the new server.

Re: NEC Question

[Rich Nute]

Hi Mike:


>   Can someone point me to a section in the NEC that says a piece of
>   RESIDENTIAL computer equipment must be "listed" (NEC definition).  Article
>   645  which requires a "listed" piece of equipment appears to apply to a
>   computer room and not a residence.

In terms of the NEC, a computer is an "appliance."
(Article 100, definitions.)  Also see the definition
for "utilization equipment."

An "appliance" is also an "equipment."  (Article 
100, definitions.)

Article 110-2 requires equipment to be "approved."

"Approved" means "acceptable to the authority 
having jurisdiction."  (Article 100, definitions.)

Article 90-7 states that "...equipment need not be
inspected at the time of installation... if the
equipment has been listed..."

"Listed" is defined in Article 100.

So, the NEC says that a residential computer must 
be Listed.

>   Basically I've been asked where its says a piece of computer equipment must
>   listed/approved by a NRTL.  I'm ignoring the obvious liability implications
>   should someone get injured for the purposes of this question..

The NEC does not require listing by a NRTL.  (NRTL 
is an OSHA concept, not a NEC concept.)  

The acceptable certification houses are defined by 
the authority having jurisdiction (the government
that is enforcing the code, i.e, the city, county, 
or state).  Many NRTLs are also accepted by all 
jurisdictions, but not necessarily so.


Best regards,
Rich



---
This message is from the IEEE EMC Society Product Safety
Technical Committee emc-pstc discussion list.

Visit our web site at:  http://www.ewh.ieee.org/soc/emcs/pstc/

To cancel your subscription, send mail to:
 majord...@ieee.org
with the single line:
 unsubscribe emc-pstc

For help, send mail to the list administrators:
 Michael Garretson:pstc_ad...@garretson.org
 Dave Healddavehe...@mediaone.net

For policy questions, send mail to:
 Richard Nute:   ri...@ieee.org
 Jim Bacher: j.bac...@ieee.org

All emc-pstc postings are archived and searchable on the web at:
No longer online until our new server is brought online and the old 
messages are imported into the new server.

Class Designation under the R&TTE directive

[Kevin Harris]

Dear Group,

I just was reading the a list to assist one in choosing one's class
designation under the R&TTE directive at
http://www.europa.eu.int/comm/enterprise/rtte/listeq.htm
  and I noticed
that there are items under Class 1 that I never saw before (i.e. items 19 to
24) It just so happens that item 20 applies to me and relieves me of having
to follow the notification period. People in the security business may want
to look at the page! Up until now we had always classified ourselves as
Class 2.7 (SRD). My question is (out of idle curiosity)  does anyone know
when items 19 to 24 were added. The page has no indications of when it was
updated but I have a printed copy from last November showing a much shorter
list.

Best Regards,


Kevin Harris
Manager, Approval Services
Digital Security Controls
3301 Langstaff Road
Concord, Ontario
CANADA
L4K 4L2

Tel: +1 905 760 3000 Ext. 2378
Fax +1 905 760 3020

Email: harr...@dscltd.com  

---
This message is from the IEEE EMC Society Product Safety
Technical Committee emc-pstc discussion list.

Visit our web site at:  http://www.ewh.ieee.org/soc/emcs/pstc/

To cancel your subscription, send mail to:
 majord...@ieee.org
with the single line:
 unsubscribe emc-pstc

For help, send mail to the list administrators:
 Michael Garretson:pstc_ad...@garretson.org
 Dave Healddavehe...@mediaone.net

For policy questions, send mail to:
 Richard Nute:   ri...@ieee.org
 Jim Bacher: j.bac...@ieee.org

All emc-pstc postings are archived and searchable on the web at:
No longer online until our new server is brought online and the old 
messages are imported into the new server.

RE: Too small to print Fcc Verification label!!!

[Benoit Nadeau]

Bonjour de Montreal,

It all depends of the procedure you used for your product :

If it is a Class B digital device using the, now obsolete, certification
process, you have to put at a minimum the FCC ID of your granted
certificate. The only way it could be used now is by the mean of a
permissive change procedure.

If it is a Class B digital device using the Declaration of Conformity (DOC)
procedure, then at a minimum the FCC logo (see attachment) has to be on the
device, all other information in the user’s manual.

If it is a Class A digital device, using a verification procedure, this is
where you have a problem because you don’t have an FCC ID and the FCC logo
is reserved to the DOCs, my suggestion in that case would be to state in
writing, FCC Class A and put all the rest of the information in the user’s
manual.

Hope this help,

Best regards,

==
Benoit Nadeau, ing., M.ing. (P.Eng., M.Eng)
Gerant du Groupe Conformite (Conformity Group Manager)
Matrox
==
Tel : (514) 822-6000 (2475)
Fax : (514) 822-6275
mailto:bnad...@matrox.com
http://www.matrox.com
==
President / Chairman
2001 IEEE International Symposium on
Electromagnetic Compatibility
mailto:bnad...@ieee.org
http://www.2001emcmtl.org

-Original Message-
From: owner-emc-p...@majordomo.ieee.org
[mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of upu...@samsung.com
Sent: Wednesday, October 24, 2001 05:17
To: emc-p...@majordomo.ieee.org; upu...@samsung.co.kr
Subject: Too small to print Fcc Verification label!!!


Hi EMC members.

I have a question about Fcc Label.

This model is too small to insert Fcc verification statement on device.
This is Compactflash memory card.

I read Fcc Part 15. rules but I couldn't understand meaning.

On Section 15.19 said "alternatively,shall be placed on the container in
which the
devide is marketed.However,the FCC identifier or the unique identifier,as
appropriate
must be displayed on the device."

I confuse from 'However...'

In conclusion,I'd like to know what can I do in case device is too small to
print Fcc verification statement on device.
Can I print only Fcc character on label?

If you have any idea,mail to me.

Best regards.

Tommy
--- This message is from the IEEE
EMC Society Product Safety Technical Committee emc-pstc discussion list.
Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your
subscription, send mail to: majord...@ieee.org with the single line:
unsubscribe emc-pstc For help, send mail to the list administrators: Michael
Garretson: pstc_ad...@garretson.org Dave Heald davehe...@mediaone.net For
policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher:
j.bac...@ieee.org All emc-pstc postings are archived and searchable on the
web at: No longer online until our new server is brought online and the old
messages are imported into the new server.
<>

Re: Insulated Electrolytic Capacitors

[Rich Nute]

Hi Peter:


As a general rule, the insulation on the outside of
an electrolytic capacitor is considered functional 
insulation.  (Indeed, the insulation between the 
elements of the capacitor and the aluminum can is
clearly functional insulation.)

As far as I know, only X- and Y-capacitor insulation
may be considered Basic insulation (in accordance 
with IEC 60384-14).

Consequently, the insulation on the capacitor must
be ignored.  The distance between the capacitor
case and grounded metal must meet the creepage and 
clearance distance requirements, or solid insulation 
must be interposed between the capacitor and the 
grounded metal.

The fact that some certified power supplies do not 
meet the spacing requirements is not an argument
that such spacings are not required.  This simply
means that neither the power supply safety engineer
nor the certification engineer caught the problem.
After all, the spacings within a power supply 
comprise a rather difficult and tedious job of 
identifying the various voltages and corresponding
creepage and clearances on the PWB two-dimensional
plane.  Often, we don't look at the clearances in 
the third, vertical dimension.


Best regards,
Rich




---
This message is from the IEEE EMC Society Product Safety
Technical Committee emc-pstc discussion list.

Visit our web site at:  http://www.ewh.ieee.org/soc/emcs/pstc/

To cancel your subscription, send mail to:
 majord...@ieee.org
with the single line:
 unsubscribe emc-pstc

For help, send mail to the list administrators:
 Michael Garretson:pstc_ad...@garretson.org
 Dave Healddavehe...@mediaone.net

For policy questions, send mail to:
 Richard Nute:   ri...@ieee.org
 Jim Bacher: j.bac...@ieee.org

All emc-pstc postings are archived and searchable on the web at:
No longer online until our new server is brought online and the old 
messages are imported into the new server.

AW: Insulated Electrolytic Capacitors

[Horst Haug]

Peter,

my experience is, that you will not receive a statement from the
manufacturer of the capacitor about the foil around the cap. This would be
required to proof, that it is good for basic insulation.

Our company (we are a GS-mark certification body) does not accept the foil
around a capacitor as basic insulation without proof. My experience with UL
is, that UL is doing the same.

The only way to accept the insulation of the capacitor would be to get a
written statement from the capacitor manufacturer about the foil and
describe  this insulation in the list of safety critical components.

With best regards
Horst

-Urspr?ngliche Nachricht-
Von: owner-emc-p...@majordomo.ieee.org
[mailto:owner-emc-p...@majordomo.ieee.org]Im Auftrag von Peter Merguerian
Gesendet: Mittwoch, 24. Oktober 2001 15:38
An: "EMC-PSTC (E-mail)" <
Betreff: Insulated Electrolytic Capacitors


Dear All,

I have submitted an ac input to dc output switching power supply for NRTL
approval. One deviation is that the primary ac insulated capacitor is too
close to the earthed chassis and that the insulation cannot be relied to
provide the required basic insulation.

1. What is the group's opinion regarding this point? I have personally seen
many Listed/Recognized units with clearance distance less than 2.0 mm to the
earthed chassis without any additional insulation to provide the required
insulation. In fact, I am holding a switching power supply by a reputable
manufacturer with only approx. 0.7 mm between the primary and earthed
chassis. This power supply is  UL Recognized and TUV approved.

2. There is a UL Pag 156002 regarding this issue, but it seems that some
NRTL engineers are using their own judgement and approving units at their
own discretion.





This e-mail message may contain privileged or confidential information. If
you are not the intended recipient, you may not disclose, use, disseminate,
distribute, copy or rely upon this message or attachment in any way. If you
received this e-mail message in error, please return by forwarding the
message and its attachments to the sender.




PETER S. MERGUERIAN
Technical Director
I.T.L. (Product Testing) Ltd.
26 Hacharoshet St., POB 211
Or Yehuda 60251, Israel
Tel: + 972-(0)3-5339022  Fax: + 972-(0)3-5339019
Mobile: + 972-(0)54-838175






---
This message is from the IEEE EMC Society Product Safety
Technical Committee emc-pstc discussion list.

Visit our web site at:  http://www.ewh.ieee.org/soc/emcs/pstc/

To cancel your subscription, send mail to:
 majord...@ieee.org
with the single line:
 unsubscribe emc-pstc

For help, send mail to the list administrators:
 Michael Garretson:pstc_ad...@garretson.org
 Dave Healddavehe...@mediaone.net

For policy questions, send mail to:
 Richard Nute:   ri...@ieee.org
 Jim Bacher: j.bac...@ieee.org

All emc-pstc postings are archived and searchable on the web at:
No longer online until our new server is brought online and the old
messages are imported into the new server.


---
This message is from the IEEE EMC Society Product Safety
Technical Committee emc-pstc discussion list.

Visit our web site at:  http://www.ewh.ieee.org/soc/emcs/pstc/

To cancel your subscription, send mail to:
 majord...@ieee.org
with the single line:
 unsubscribe emc-pstc

For help, send mail to the list administrators:
 Michael Garretson:pstc_ad...@garretson.org
 Dave Healddavehe...@mediaone.net

For policy questions, send mail to:
 Richard Nute:   ri...@ieee.org
 Jim Bacher: j.bac...@ieee.org

All emc-pstc postings are archived and searchable on the web at:
No longer online until our new server is brought online and the old 
messages are imported into the new server.

RE: Insulated Electrolytic Capacitors

[Jim Eichner]

I asked a similar question a couple of years ago, and was told that the
bodies of plastic encapsulated Y1 capacitors are considered by CENELEC to be
reinforced insulation, except in the vicinity of the leads.  I don't know if
this extends to types of  X and Y caps other than Y1.

Hope this is some help,

Regards, 
Jim Eichner, P.Eng. 
Manager, Engineering Services 
Xantrex Technology Inc. 
Mobile Power
web: www.xantrex.com  

Any opinions expressed are those of my invisible friend, who really
exists.  I know because he talks to me.  Honest.



-Original Message-
From: Peter Merguerian [mailto:pmerguer...@itl.co.il]
Sent: Wednesday, October 24, 2001 6:38 AM
To: "EMC-PSTC (E-mail)" <
Subject: Insulated Electrolytic Capacitors



Dear All,

I have submitted an ac input to dc output switching power supply for NRTL
approval. One deviation is that the primary ac insulated capacitor is too
close to the earthed chassis and that the insulation cannot be relied to
provide the required basic insulation. 

1. What is the group's opinion regarding this point? I have personally seen
many Listed/Recognized units with clearance distance less than 2.0 mm to the
earthed chassis without any additional insulation to provide the required
insulation. In fact, I am holding a switching power supply by a reputable
manufacturer with only approx. 0.7 mm between the primary and earthed
chassis. This power supply is  UL Recognized and TUV approved.

2. There is a UL Pag 156002 regarding this issue, but it seems that some
NRTL engineers are using their own judgement and approving units at their
own discretion.





This e-mail message may contain privileged or confidential information. If
you are not the intended recipient, you may not disclose, use, disseminate,
distribute, copy or rely upon this message or attachment in any way. If you
received this e-mail message in error, please return by forwarding the
message and its attachments to the sender.




PETER S. MERGUERIAN
Technical Director
I.T.L. (Product Testing) Ltd.
26 Hacharoshet St., POB 211
Or Yehuda 60251, Israel
Tel: + 972-(0)3-5339022  Fax: + 972-(0)3-5339019
Mobile: + 972-(0)54-838175






---
This message is from the IEEE EMC Society Product Safety
Technical Committee emc-pstc discussion list.

Visit our web site at:  http://www.ewh.ieee.org/soc/emcs/pstc/

To cancel your subscription, send mail to:
 majord...@ieee.org
with the single line:
 unsubscribe emc-pstc

For help, send mail to the list administrators:
 Michael Garretson:pstc_ad...@garretson.org
 Dave Healddavehe...@mediaone.net

For policy questions, send mail to:
 Richard Nute:   ri...@ieee.org
 Jim Bacher: j.bac...@ieee.org

All emc-pstc postings are archived and searchable on the web at:
No longer online until our new server is brought online and the old
messages are imported into the new server.

---
This message is from the IEEE EMC Society Product Safety
Technical Committee emc-pstc discussion list.

Visit our web site at:  http://www.ewh.ieee.org/soc/emcs/pstc/

To cancel your subscription, send mail to:
 majord...@ieee.org
with the single line:
 unsubscribe emc-pstc

For help, send mail to the list administrators:
 Michael Garretson:pstc_ad...@garretson.org
 Dave Healddavehe...@mediaone.net

For policy questions, send mail to:
 Richard Nute:   ri...@ieee.org
 Jim Bacher: j.bac...@ieee.org

All emc-pstc postings are archived and searchable on the web at:
No longer online until our new server is brought online and the old 
messages are imported into the new server.

Tantalum Capacitors

[liviu_dinulescu]

Hi all,
Some companies make through-hole polarized caps which cannot be loaded
backwards; they are 3 pin in-line parts that are assigned +/-/+.  Does
anyone make SM parts that have the same attribute of not capable of being
loaded backwards?

Also where may I find reliability data for the so called "solid
electrolytic" capacitors as SANYO OS-CON or POSCAP.

-Liviu Dinulescu
Teradyne Inc.



---
This message is from the IEEE EMC Society Product Safety
Technical Committee emc-pstc discussion list.

Visit our web site at:  http://www.ewh.ieee.org/soc/emcs/pstc/

To cancel your subscription, send mail to:
 majord...@ieee.org
with the single line:
 unsubscribe emc-pstc

For help, send mail to the list administrators:
 Michael Garretson:pstc_ad...@garretson.org
 Dave Healddavehe...@mediaone.net

For policy questions, send mail to:
 Richard Nute:   ri...@ieee.org
 Jim Bacher: j.bac...@ieee.org

All emc-pstc postings are archived and searchable on the web at:
No longer online until our new server is brought online and the old 
messages are imported into the new server.

RE: NEC Question

[WOODS]

Mike, regardless of what the NEC says, and it is not very clear in this
regard, it is the state, county and city electrical codes and other local
regulations that apply. Many jurisdictions have deviations from the NEC
and/or have other regulations that require electrical equipment sold to the
general public be Listed. I know of the following locations: Virginia, North
Carolina, Los Angeles, Counties of Los Angeles and Orange, and San
Francisco. I have also heard but cannot confirm that other locations include
Oregon, Washington, New York city and Chicago.

Richard Woods
Sensormatic Electronics


-Original Message-
From: Mike Morrow [mailto:mi...@ucentric.com]
Sent: Wednesday, October 24, 2001 11:52 AM
To: EMC Society
Subject: NEC Question



Can someone point me to a section in the NEC that says a piece of
RESIDENTIAL computer equipment must be "listed" (NEC definition).  Article
645  which requires a "listed" piece of equipment appears to apply to a
computer room and not a residence.

Basically I've been asked where its says a piece of computer equipment must
listed/approved by a NRTL.  I'm ignoring the obvious liability implications
should someone get injured for the purposes of this question..

Any help is appreciated.

Mike Morrow
Senior Compliance Engineer
Ucentric Systems, LLC
978-823-8166
mi...@ucentric.com


---
This message is from the IEEE EMC Society Product Safety
Technical Committee emc-pstc discussion list.

Visit our web site at:  http://www.ewh.ieee.org/soc/emcs/pstc/

To cancel your subscription, send mail to:
 majord...@ieee.org
with the single line:
 unsubscribe emc-pstc

For help, send mail to the list administrators:
 Michael Garretson:pstc_ad...@garretson.org
 Dave Healddavehe...@mediaone.net

For policy questions, send mail to:
 Richard Nute:   ri...@ieee.org
 Jim Bacher: j.bac...@ieee.org

All emc-pstc postings are archived and searchable on the web at:
No longer online until our new server is brought online and the old
messages are imported into the new server.

---
This message is from the IEEE EMC Society Product Safety
Technical Committee emc-pstc discussion list.

Visit our web site at:  http://www.ewh.ieee.org/soc/emcs/pstc/

To cancel your subscription, send mail to:
 majord...@ieee.org
with the single line:
 unsubscribe emc-pstc

For help, send mail to the list administrators:
 Michael Garretson:pstc_ad...@garretson.org
 Dave Healddavehe...@mediaone.net

For policy questions, send mail to:
 Richard Nute:   ri...@ieee.org
 Jim Bacher: j.bac...@ieee.org

All emc-pstc postings are archived and searchable on the web at:
No longer online until our new server is brought online and the old 
messages are imported into the new server.

skinny power cords.

[Gary McInturff]

Fuses and breakers etc, are provided to protect the wiring
downstream from these devices. A 15 amp breaker is allowed to have 14 AWG
wire attached and run all though my house, and terminates in a 15 amp rated
receptacle - parallel blade with ground pin.
Why then can I plug in a computer that has only a 6 or 10 amp rated
power cord? Surely, its not because the computer has supplemental fusing at
2 amps or whatever. That 2 amp fuse can't protect the wiring between it and
the 15 amp breaker in my garage from prolonged operation at 15 amps. The
breaker is completely happy running at that value so the wire just sits
there and cooks!
One would think that any  cord rated less than 15 amps, would have
to be terminated in a plug that doesn't mate with the wall outlet, much like
a 15 amp connector plugged into a 20 amp outlet.
Gary

---
This message is from the IEEE EMC Society Product Safety
Technical Committee emc-pstc discussion list.

Visit our web site at:  http://www.ewh.ieee.org/soc/emcs/pstc/

To cancel your subscription, send mail to:
 majord...@ieee.org
with the single line:
 unsubscribe emc-pstc

For help, send mail to the list administrators:
 Michael Garretson:pstc_ad...@garretson.org
 Dave Healddavehe...@mediaone.net

For policy questions, send mail to:
 Richard Nute:   ri...@ieee.org
 Jim Bacher: j.bac...@ieee.org

All emc-pstc postings are archived and searchable on the web at:
No longer online until our new server is brought online and the old 
messages are imported into the new server.

NEC Question

[Mike Morrow]

Can someone point me to a section in the NEC that says a piece of
RESIDENTIAL computer equipment must be "listed" (NEC definition).  Article
645  which requires a "listed" piece of equipment appears to apply to a
computer room and not a residence.

Basically I've been asked where its says a piece of computer equipment must
listed/approved by a NRTL.  I'm ignoring the obvious liability implications
should someone get injured for the purposes of this question..

Any help is appreciated.

Mike Morrow
Senior Compliance Engineer
Ucentric Systems, LLC
978-823-8166
mi...@ucentric.com


---
This message is from the IEEE EMC Society Product Safety
Technical Committee emc-pstc discussion list.

Visit our web site at:  http://www.ewh.ieee.org/soc/emcs/pstc/

To cancel your subscription, send mail to:
 majord...@ieee.org
with the single line:
 unsubscribe emc-pstc

For help, send mail to the list administrators:
 Michael Garretson:pstc_ad...@garretson.org
 Dave Healddavehe...@mediaone.net

For policy questions, send mail to:
 Richard Nute:   ri...@ieee.org
 Jim Bacher: j.bac...@ieee.org

All emc-pstc postings are archived and searchable on the web at:
No longer online until our new server is brought online and the old 
messages are imported into the new server.

Re: Insulated Electrolytic Capacitors

[Patrick Lawler]

Our company manufactures switching power supplies to EN60950 and EN60601-1
standards, and our safety group looks for these issues.
In fact, I got 'bit' by that same problem last week.  Spacing was OK when the
PWB was mounted in the chassis, but when the cover was installed, it failed
primary-ground spacing.  I had to fix it.

As far as the sample power supplies you have:
- What safety standard does the manufacturer claim?
- What are the installation instructions, or 'conditions of acceptability'?
- Did they look as if they had been modified or installed in another chassis
assembly after it was manufactured?


On Wed, 24 Oct 2001 15:38:19 +0200, Peter Merguerian 
wrote:
>I have submitted an ac input to dc output switching power supply for NRTL
>approval. One deviation is that the primary ac insulated capacitor is too
>close to the earthed chassis and that the insulation cannot be relied to
>provide the required basic insulation. 
>
>1. What is the group's opinion regarding this point? I have personally seen
>many Listed/Recognized units with clearance distance less than 2.0 mm to the
>earthed chassis without any additional insulation to provide the required
>insulation. In fact, I am holding a switching power supply by a reputable
>manufacturer with only approx. 0.7 mm between the primary and earthed
>chassis. This power supply is  UL Recognized and TUV approved.
>
>2. There is a UL Pag 156002 regarding this issue, but it seems that some
>NRTL engineers are using their own judgement and approving units at their
>own discretion.

---
This message is from the IEEE EMC Society Product Safety
Technical Committee emc-pstc discussion list.

Visit our web site at:  http://www.ewh.ieee.org/soc/emcs/pstc/

To cancel your subscription, send mail to:
 majord...@ieee.org
with the single line:
 unsubscribe emc-pstc

For help, send mail to the list administrators:
 Michael Garretson:pstc_ad...@garretson.org
 Dave Healddavehe...@mediaone.net

For policy questions, send mail to:
 Richard Nute:   ri...@ieee.org
 Jim Bacher: j.bac...@ieee.org

All emc-pstc postings are archived and searchable on the web at:
No longer online until our new server is brought online and the old 
messages are imported into the new server.

RE: TNV Circuits

[Bill Owsley]

It's over on Bizarre Street.

At 10:33 AM 10/24/2001 , Cortland Richmond wrote:


>> telephone products destroyed by all sorts of bazaar events <<

Where IS that bazaar? (grin)

Cortland

---
This message is from the IEEE EMC Society Product Safety
Technical Committee emc-pstc discussion list.

Visit our web site at:  http://www.ewh.ieee.org/soc/emcs/pstc/

To cancel your subscription, send mail to:
 majord...@ieee.org
with the single line:
 unsubscribe emc-pstc

For help, send mail to the list administrators:
 Michael Garretson:pstc_ad...@garretson.org
 Dave Healddavehe...@mediaone.net

For policy questions, send mail to:
 Richard Nute:   ri...@ieee.org
 Jim Bacher: j.bac...@ieee.org

All emc-pstc postings are archived and searchable on the web at:
No longer online until our new server is brought online and the old 
messages are imported into the new server.


-
British Prime Minister Tony Blair pointed to the victims of the Sept. 11 
attacks on the World Trade Center and the Pentagon, and said the Taliban 
regime had no "moral inhibition" on slaughtering innocent people.


"There is no compromise possible with such people, no meeting of minds, no 
point of understanding with
such terror," he said. "There is just a choice: Defeat it or be defeated by 
it and defeat it we must."


"Whatever the dangers of the action we take, the dangers of inaction are 
far, far greater," he said.


Bill Owsley,   ows...@cisco.com
919) 392-8341

Compliance Engineer
Cisco Systems
7025 Kit Creek Road
POB 14987
RTP. NC. 27709



---
This message is from the IEEE EMC Society Product Safety
Technical Committee emc-pstc discussion list.

Visit our web site at:  http://www.ewh.ieee.org/soc/emcs/pstc/

To cancel your subscription, send mail to:
majord...@ieee.org
with the single line:
unsubscribe emc-pstc

For help, send mail to the list administrators:
Michael Garretson:pstc_ad...@garretson.org
Dave Healddavehe...@mediaone.net

For policy questions, send mail to:
Richard Nute:   ri...@ieee.org
Jim Bacher: j.bac...@ieee.org

All emc-pstc postings are archived and searchable on the web at:
   No longer online until our new server is brought online and the old messages 
are imported into the new server.

RE: EFT Failures..Update!

[Hare, Paul]

Alex, make sure you investigate whether or not energy is coupling to other
cables of the EUT and causing problems.  In other words, try to reduce the
system (remove cables) and see if the EFT failures persist.  If you can't
remove a cable due to functionality, place ferrites on it instead (near the
EUT).   You may be surprised how a failure manifests itself.  Sometimes
you've got to back up and take a look at the forest...  :)

Good luck...

Paul Hare   e: ph...@pirus.com
Compliance Engineer w: 978.206.9179
Pirus Networks  f: 978.206.9199
43 Nagog Park   c: 508.450.0376
Acton, MA 01720 i: www.pirus.com


-Original Message-
From: am...@westin-emission.no [mailto:am...@westin-emission.no]
Sent: Wednesday, October 24, 2001 4:04 AM
To: emc-p...@majordomo.ieee.org
Subject: SV: EFT Failures..Update!



Alex,

What happened during the burst test ? Did the EUT break down or did you only
have minor disturbances/faults during the test ?

I assume that you know that EFT/bursts usually is a performance criteria B
test, which means that temporary faults are accepted during the test, as
long that the EUT is self-recoverable after the test.

Amund

-Opprinnelig melding-
Fra: owner-emc-p...@majordomo.ieee.org
[mailto:owner-emc-p...@majordomo.ieee.org]På vegne av Alex McNeil
Sendt: 23. oktober 2001 10:44
Til: 'emc-p...@majordomo.ieee.org'
Emne: EFT Failures..Update!




Hi Group,

THANKS for your very much appreciated responses!! I was in panic mode!!

I thought it would be appropriate to let you know the status.

My product is a small all plastic enclosure Point if Sale (POS) Class III
terminal. It has an external SMPS, Class II, no earth, supplying SELV, 12Vdc
1.5A to my product. The power supply works OK with some of our other
products, for EMC. The problem is with my product.

I solved the problem at the test house by wrapping a few turns of the DC PSU
cable through a "Large" Ferrite Clamp at the Product input (it did not work
so well at the PSU I/P nor O/P). The fix cannot be considered final due to
obvious reasons.

I am now at my Lab, now the serious diagnostics begin. I have been trying
various "quick fixes" to no avail i.e. Caps, TVS, MOV etc.

If you have any further comments feel free to email me.

THANKS again to all those who responded with their thoughts. I can tell you
they were wide and varied just as you would expect to trying to resolve an
EMC problem over the NET!!

Best Regards
alex.mcn...@ingenicofortronic.com








>  -Original Message-
> From: Alex McNeil
> Sent: 22 October 2001 11:23
> To:   emc-p...@majordomo.ieee.org
> Subject:  EFT Failures..Help!
>
> Hi Guys,
>
> I am at an EMC test centre today and tomorrow. Unfortunately, my product
> failed EFT testing on the AC power port at 1KV. This is for various
> combinations of Line, Neutral and Earth (L, N, E, LN, LE, NE and LNE)
>
> My product is Class II, no Earth. It is supplied by an external power
> supply. This supplies SELV to my product. The power supply manufacturer
> has stated that his power supply meets EN61000-4-4 for 2KV and has emailed
> me this report to verify this.
>
> Has anyone got a quick solution to my problem so that I can implement here
> at the EMC test house?
>
> Kind Regards
> Alex McNeil
> Principal Engineer
> Tel: +44 (0)131 479 8375
> Fax: +44 (0)131 479 8321
> email: alex.mcn...@ingenicofortronic.com
>

---
This message is from the IEEE EMC Society Product Safety
Technical Committee emc-pstc discussion list.

Visit our web site at:  http://www.ewh.ieee.org/soc/emcs/pstc/

To cancel your subscription, send mail to:
 majord...@ieee.org
with the single line:
 unsubscribe emc-pstc

For help, send mail to the list administrators:
 Michael Garretson:pstc_ad...@garretson.org
 Dave Healddavehe...@mediaone.net

For policy questions, send mail to:
 Richard Nute:   ri...@ieee.org
 Jim Bacher: j.bac...@ieee.org

All emc-pstc postings are archived and searchable on the web at:
No longer online until our new server is brought online and the old
messages are imported into the new server.



---
This message is from the IEEE EMC Society Product Safety
Technical Committee emc-pstc discussion list.

Visit our web site at:  http://www.ewh.ieee.org/soc/emcs/pstc/

To cancel your subscription, send mail to:
 majord...@ieee.org
with the single line:
 unsubscribe emc-pstc

For help, send mail to the list administrators:
 Michael Garretson:pstc_ad...@garretson.org
 Dave Healddavehe...@mediaone.net

For policy questions, send mail to:
 Richard Nute:   ri...@ieee.org
 Jim Bacher: j.bac...@ieee.org

All emc-pstc postings are archived and searchable on the web at:
No longer online until our new server is brought online and the old
messages are importe

RE: TNV Circuits

[Cortland Richmond]

>> telephone products destroyed by all sorts of bazaar events <<

Where IS that bazaar? (grin)

Cortland

---
This message is from the IEEE EMC Society Product Safety
Technical Committee emc-pstc discussion list.

Visit our web site at:  http://www.ewh.ieee.org/soc/emcs/pstc/

To cancel your subscription, send mail to:
 majord...@ieee.org
with the single line:
 unsubscribe emc-pstc

For help, send mail to the list administrators:
 Michael Garretson:pstc_ad...@garretson.org
 Dave Healddavehe...@mediaone.net

For policy questions, send mail to:
 Richard Nute:   ri...@ieee.org
 Jim Bacher: j.bac...@ieee.org

All emc-pstc postings are archived and searchable on the web at:
No longer online until our new server is brought online and the old 
messages are imported into the new server.

Insulated Electrolytic Capacitors

[Peter Merguerian]

Dear All,

I have submitted an ac input to dc output switching power supply for NRTL
approval. One deviation is that the primary ac insulated capacitor is too
close to the earthed chassis and that the insulation cannot be relied to
provide the required basic insulation. 

1. What is the group's opinion regarding this point? I have personally seen
many Listed/Recognized units with clearance distance less than 2.0 mm to the
earthed chassis without any additional insulation to provide the required
insulation. In fact, I am holding a switching power supply by a reputable
manufacturer with only approx. 0.7 mm between the primary and earthed
chassis. This power supply is  UL Recognized and TUV approved.

2. There is a UL Pag 156002 regarding this issue, but it seems that some
NRTL engineers are using their own judgement and approving units at their
own discretion.





This e-mail message may contain privileged or confidential information. If
you are not the intended recipient, you may not disclose, use, disseminate,
distribute, copy or rely upon this message or attachment in any way. If you
received this e-mail message in error, please return by forwarding the
message and its attachments to the sender.




PETER S. MERGUERIAN
Technical Director
I.T.L. (Product Testing) Ltd.
26 Hacharoshet St., POB 211
Or Yehuda 60251, Israel
Tel: + 972-(0)3-5339022  Fax: + 972-(0)3-5339019
Mobile: + 972-(0)54-838175






---
This message is from the IEEE EMC Society Product Safety
Technical Committee emc-pstc discussion list.

Visit our web site at:  http://www.ewh.ieee.org/soc/emcs/pstc/

To cancel your subscription, send mail to:
 majord...@ieee.org
with the single line:
 unsubscribe emc-pstc

For help, send mail to the list administrators:
 Michael Garretson:pstc_ad...@garretson.org
 Dave Healddavehe...@mediaone.net

For policy questions, send mail to:
 Richard Nute:   ri...@ieee.org
 Jim Bacher: j.bac...@ieee.org

All emc-pstc postings are archived and searchable on the web at:
No longer online until our new server is brought online and the old 
messages are imported into the new server.

RE: TNV Circuits

[Gregg Kervill]

Thanks Joe - that was the very point that I was trying to make - and that is
why TNV is treated as hazardous.
  -Original Message-
  From: owner-emc-p...@majordomo.ieee.org
[mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of j...@aol.com
  Sent: Tuesday, October 23, 2001 10:44 PM
  To: gkerv...@eu-link.com; phopk...@ga.conklincorp.com;
emc-p...@majordomo.ieee.org
  Subject: Re: TNV Circuits


  In a message dated 10/23/01, Gregg Kervill writes:



Have lines ever been struck by  Lightning?

One of my clients had a cupboard full of telephone products destroyed by
all sorts of bazaar events - like the temporary three phase power line to a
factory that "fell' across domestic phone lines

Anything outside must be considered hazardous and if that hazard is
limited to +_200 then we are VERY lucky.




  Hi Gregg:

  UL 60950 makes a distinction between working voltages that are present all
the time (such as span power) and transient overvoltages caused by lightning
and power cross.  Both types of situations are addressed in the standard,
but they are treated differently, as they should be.


  Joe Randolph
  Telecom Design Consultant
  Randolph Telecom, Inc.
  http://www.randolph-telecom.com

Standards applicable to crane equipment

[Kristiaan . Carpentier]

Dear all,

The product concerned is a metal box located on the (metal) roller bridge of a 
crane and controls the movement of that bridge.
It is powered by min. 48Vac and receives commands from an operator with a 
battery powered hand-held radio transmitter command box.
The 48V ac power supply is connected to the metal frame of the roller bridge.
The crane nor roller bridge are connected to ground by means of a fixed 
connection.
All additional metal parts are connected to the fixed or moving part of the 
crane.

Questions:
1.- What standards and regulations are applicable to both products for EMC, 
Safety and Radio,  for US and EU market?
2.- Can the metal frame be considered as "reliably connected to PE"?

Regards,
Kris Carpentier



---
This message is from the IEEE EMC Society Product Safety
Technical Committee emc-pstc discussion list.

Visit our web site at:  http://www.ewh.ieee.org/soc/emcs/pstc/

To cancel your subscription, send mail to:
 majord...@ieee.org
with the single line:
 unsubscribe emc-pstc

For help, send mail to the list administrators:
 Michael Garretson:pstc_ad...@garretson.org
 Dave Healddavehe...@mediaone.net

For policy questions, send mail to:
 Richard Nute:   ri...@ieee.org
 Jim Bacher: j.bac...@ieee.org

All emc-pstc postings are archived and searchable on the web at:
No longer online until our new server is brought online and the old 
messages are imported into the new server.

Too small to print Fcc Verification label!!!

[upuaut]

 

 Hi EMC members.
 
I have a question about Fcc Label.
 
This model is too small to insert Fcc verification statement on device.
This is Compactflash memory card.
 
I read Fcc Part 15. rules but I couldn't understand meaning.
 
On Section 15.19 said "alternatively,shall be placed on the container in which the 
devide is marketed.However,the FCC identifier or the unique identifier,as appropriate
must be displayed on the device."
 
I confuse from 'However...'
 
In conclusion,I'd like to know what can I do in case device is too small to 
print Fcc verification statement on device.
Can I print only Fcc character on label?
 
If you have any idea,mail to me.
 
Best regards.
 
Tommy


---
This message is from the IEEE EMC Society Product Safety
Technical Committee emc-pstc discussion list.

Visit our web site at:  http://www.ewh.ieee.org/soc/emcs/pstc/

To cancel your subscription, send mail to:
 majord...@ieee.org
with the single line:
 unsubscribe emc-pstc

For help, send mail to the list administrators:
 Michael Garretson:pstc_ad...@garretson.org
 Dave Healddavehe...@mediaone.net

For policy questions, send mail to:
 Richard Nute:   ri...@ieee.org
 Jim Bacher: j.bac...@ieee.org

All emc-pstc postings are archived and searchable on the web at:
No longer online until our new server is brought online and the old messages are imported into the new server.

SV: EFT Failures..Update!

[amund]

Alex,

What happened during the burst test ? Did the EUT break down or did you only
have minor disturbances/faults during the test ?

I assume that you know that EFT/bursts usually is a performance criteria B
test, which means that temporary faults are accepted during the test, as
long that the EUT is self-recoverable after the test.

Amund

-Opprinnelig melding-
Fra: owner-emc-p...@majordomo.ieee.org
[mailto:owner-emc-p...@majordomo.ieee.org]På vegne av Alex McNeil
Sendt: 23. oktober 2001 10:44
Til: 'emc-p...@majordomo.ieee.org'
Emne: EFT Failures..Update!




Hi Group,

THANKS for your very much appreciated responses!! I was in panic mode!!

I thought it would be appropriate to let you know the status.

My product is a small all plastic enclosure Point if Sale (POS) Class III
terminal. It has an external SMPS, Class II, no earth, supplying SELV, 12Vdc
1.5A to my product. The power supply works OK with some of our other
products, for EMC. The problem is with my product.

I solved the problem at the test house by wrapping a few turns of the DC PSU
cable through a "Large" Ferrite Clamp at the Product input (it did not work
so well at the PSU I/P nor O/P). The fix cannot be considered final due to
obvious reasons.

I am now at my Lab, now the serious diagnostics begin. I have been trying
various "quick fixes" to no avail i.e. Caps, TVS, MOV etc.

If you have any further comments feel free to email me.

THANKS again to all those who responded with their thoughts. I can tell you
they were wide and varied just as you would expect to trying to resolve an
EMC problem over the NET!!

Best Regards
alex.mcn...@ingenicofortronic.com








>  -Original Message-
> From: Alex McNeil
> Sent: 22 October 2001 11:23
> To:   emc-p...@majordomo.ieee.org
> Subject:  EFT Failures..Help!
>
> Hi Guys,
>
> I am at an EMC test centre today and tomorrow. Unfortunately, my product
> failed EFT testing on the AC power port at 1KV. This is for various
> combinations of Line, Neutral and Earth (L, N, E, LN, LE, NE and LNE)
>
> My product is Class II, no Earth. It is supplied by an external power
> supply. This supplies SELV to my product. The power supply manufacturer
> has stated that his power supply meets EN61000-4-4 for 2KV and has emailed
> me this report to verify this.
>
> Has anyone got a quick solution to my problem so that I can implement here
> at the EMC test house?
>
> Kind Regards
> Alex McNeil
> Principal Engineer
> Tel: +44 (0)131 479 8375
> Fax: +44 (0)131 479 8321
> email: alex.mcn...@ingenicofortronic.com
>

---
This message is from the IEEE EMC Society Product Safety
Technical Committee emc-pstc discussion list.

Visit our web site at:  http://www.ewh.ieee.org/soc/emcs/pstc/

To cancel your subscription, send mail to:
 majord...@ieee.org
with the single line:
 unsubscribe emc-pstc

For help, send mail to the list administrators:
 Michael Garretson:pstc_ad...@garretson.org
 Dave Healddavehe...@mediaone.net

For policy questions, send mail to:
 Richard Nute:   ri...@ieee.org
 Jim Bacher: j.bac...@ieee.org

All emc-pstc postings are archived and searchable on the web at:
No longer online until our new server is brought online and the old
messages are imported into the new server.



---
This message is from the IEEE EMC Society Product Safety
Technical Committee emc-pstc discussion list.

Visit our web site at:  http://www.ewh.ieee.org/soc/emcs/pstc/

To cancel your subscription, send mail to:
 majord...@ieee.org
with the single line:
 unsubscribe emc-pstc

For help, send mail to the list administrators:
 Michael Garretson:pstc_ad...@garretson.org
 Dave Healddavehe...@mediaone.net

For policy questions, send mail to:
 Richard Nute:   ri...@ieee.org
 Jim Bacher: j.bac...@ieee.org

All emc-pstc postings are archived and searchable on the web at:
No longer online until our new server is brought online and the old 
messages are imported into the new server.

SV: EMC testing above 1GHz

[amund]

Hi Cecil,

You're coming up with a good question, but could you be more precise what
you are looking for ? Limits? EUT configuration ? Measurement equipment?
. You name it! EMC above 1GHz could fill serveral pages 

Best regards
Amund Westin, Oslo/Norway

-Opprinnelig melding-
Fra: owner-emc-p...@majordomo.ieee.org
[mailto:owner-emc-p...@majordomo.ieee.org]Pa vegne av
cecil.gitt...@kodak.com
Sendt: 23. oktober 2001 18:36
Til: emc-p...@majordomo.ieee.org
Emne: EMC testing above 1GHz
Viktighet: Hoy



From: Cecil A. Gittens

What are the EMC requirements for testing above 1 GHz in an Open Area test
site?


Cecil


---
This message is from the IEEE EMC Society Product Safety
Technical Committee emc-pstc discussion list.

Visit our web site at:  http://www.ewh.ieee.org/soc/emcs/pstc/

To cancel your subscription, send mail to:
 majord...@ieee.org
with the single line:
 unsubscribe emc-pstc

For help, send mail to the list administrators:
 Michael Garretson:pstc_ad...@garretson.org
 Dave Healddavehe...@mediaone.net

For policy questions, send mail to:
 Richard Nute:   ri...@ieee.org
 Jim Bacher: j.bac...@ieee.org

All emc-pstc postings are archived and searchable on the web at:
No longer online until our new server is brought online and the old
messages are imported into the new server.



---
This message is from the IEEE EMC Society Product Safety
Technical Committee emc-pstc discussion list.

Visit our web site at:  http://www.ewh.ieee.org/soc/emcs/pstc/

To cancel your subscription, send mail to:
 majord...@ieee.org
with the single line:
 unsubscribe emc-pstc

For help, send mail to the list administrators:
 Michael Garretson:pstc_ad...@garretson.org
 Dave Healddavehe...@mediaone.net

For policy questions, send mail to:
 Richard Nute:   ri...@ieee.org
 Jim Bacher: j.bac...@ieee.org

All emc-pstc postings are archived and searchable on the web at:
No longer online until our new server is brought online and the old 
messages are imported into the new server.

Re: TNV Circuits

[JPR3]

In a message dated 10/23/01, Gregg Kervill writes:


> Have lines ever been struck by  Lightning?
>  
> One of my clients had a cupboard full of telephone products destroyed by 
> all sorts of bazaar events - like the temporary three phase power line to a 
> factory that "fell' across domestic phone lines
> 
> Anything outside must be considered hazardous and if that hazard is limited 
> to +_200 then we are VERY lucky.
> 


Hi Gregg:

UL 60950 makes a distinction between working voltages that are present all 
the time (such as span power) and transient overvoltages caused by lightning 
and power cross.  Both types of situations are addressed in the standard, but 
they are treated differently, as they should be.


Joe Randolph
Telecom Design Consultant
Randolph Telecom, Inc.
http://www.randolph-telecom.com

SV: EMC testing above 1GHz

[amund]

Hi Cecil,

You're coming up with a good question, but could you be more precise what
you are looking for ? Limits? EUT configuration ? Measurement equipment?
. You name it! EMC above 1GHz could fill serveral pages 

Best regards
Amund Westin, Oslo/Norway

-Opprinnelig melding-
Fra: owner-emc-p...@majordomo.ieee.org
[mailto:owner-emc-p...@majordomo.ieee.org]Pa vegne av
cecil.gitt...@kodak.com
Sendt: 23. oktober 2001 18:36
Til: emc-p...@majordomo.ieee.org
Emne: EMC testing above 1GHz
Viktighet: Hoy



From: Cecil A. Gittens

What are the EMC requirements for testing above 1 GHz in an Open Area test
site?


Cecil


---
This message is from the IEEE EMC Society Product Safety
Technical Committee emc-pstc discussion list.

Visit our web site at:  http://www.ewh.ieee.org/soc/emcs/pstc/

To cancel your subscription, send mail to:
 majord...@ieee.org
with the single line:
 unsubscribe emc-pstc

For help, send mail to the list administrators:
 Michael Garretson:pstc_ad...@garretson.org
 Dave Healddavehe...@mediaone.net

For policy questions, send mail to:
 Richard Nute:   ri...@ieee.org
 Jim Bacher: j.bac...@ieee.org

All emc-pstc postings are archived and searchable on the web at:
No longer online until our new server is brought online and the old
messages are imported into the new server.



---
This message is from the IEEE EMC Society Product Safety
Technical Committee emc-pstc discussion list.

Visit our web site at:  http://www.ewh.ieee.org/soc/emcs/pstc/

To cancel your subscription, send mail to:
 majord...@ieee.org
with the single line:
 unsubscribe emc-pstc

For help, send mail to the list administrators:
 Michael Garretson:pstc_ad...@garretson.org
 Dave Healddavehe...@mediaone.net

For policy questions, send mail to:
 Richard Nute:   ri...@ieee.org
 Jim Bacher: j.bac...@ieee.org

All emc-pstc postings are archived and searchable on the web at:
No longer online until our new server is brought online and the old 
messages are imported into the new server.

RE: Shrunk-die power MOSFET's and compliance

[Jim Eichner]

No takers?  I haven't had any responses, but I can't believe that ins't an
issue for many of you.  The switch-mode power supplies used in almost all
equipment these days are the main users of these FET's, and the FET design
change does effect compliance.

Have none of you run into this issue? 


Jim Eichner, P.Eng.
Manager, Engineering Services
Xantrex Technology Inc.
Mobile Power
phone:  (604) 422-2546
fax:  (604) 420-1591
e-mail:  jim.eich...@xantrex.com
web: www.xantrex.com 


-Original Message-
From: Jim Eichner [mailto:jim.eich...@xantrex.com]
Sent: Wednesday, October 17, 2001 5:11 PM
To: 'EMC-PSTC - forum'
Subject: Shrunk-die power MOSFET's and compliance



I'm curious what others in the compliance community have experienced over
the last year or so in regards to re-designed power MOSFET's that the big
FET manufacturers are pushing on us.  These next generation "trench" style
FET's have smaller dies, resulting in lower on-resistance but higher thermal
impedance to their cases, and in lower gate capacitances and faster rise
times.  

At first glance it seems obvious these changes could impact the compliance
of power conversion products in the areas of emissions (increase due to
faster rise times), susceptibility to surges, and perhaps temperatures (not
that agencies care about FET temperatures, but if they're hotter
neighbouring components may be too).

The FET's involved are some of the highest volume parts these mfr's make (to
achieve maximum savings), and are widely used in power electronics.  Since
most products either are, use, or contain power electronics these days, I'd
expect this issue to be affecting almost all of us.

I'd be glad to hear of any experiences the forum has had with this issue.

Thanks,
Jim Eichner, P.Eng. 
Manager, Engineering Services 
Xantrex Technology Inc. 
Mobile Power
web: www.xantrex.com
Any opinions expressed are those of my invisible friend, who really exists.
Honest.


---
This message is from the IEEE EMC Society Product Safety
Technical Committee emc-pstc discussion list.

Visit our web site at:  http://www.ewh.ieee.org/soc/emcs/pstc/

To cancel your subscription, send mail to:
 majord...@ieee.org
with the single line:
 unsubscribe emc-pstc

For help, send mail to the list administrators:
 Michael Garretson:pstc_ad...@garretson.org
 Dave Healddavehe...@mediaone.net

For policy questions, send mail to:
 Richard Nute:   ri...@ieee.org
 Jim Bacher: j.bac...@ieee.org

All emc-pstc postings are archived and searchable on the web at:
No longer online until our new server is brought online and the old
messages are imported into the new server.

---
This message is from the IEEE EMC Society Product Safety
Technical Committee emc-pstc discussion list.

Visit our web site at:  http://www.ewh.ieee.org/soc/emcs/pstc/

To cancel your subscription, send mail to:
 majord...@ieee.org
with the single line:
 unsubscribe emc-pstc

For help, send mail to the list administrators:
 Michael Garretson:pstc_ad...@garretson.org
 Dave Healddavehe...@mediaone.net

For policy questions, send mail to:
 Richard Nute:   ri...@ieee.org
 Jim Bacher: j.bac...@ieee.org

All emc-pstc postings are archived and searchable on the web at:
No longer online until our new server is brought online and the old 
messages are imported into the new server.

RE: TNV Circuits

[Gregg Kervill]

Have lines ever been struck by  Lightning?



One of my clients had a cupboard full of telephone products destroyed by all
sorts of bazaar events - like the temporary three phase power line to a
factory that "fell' across domestic phone lines


Anything outside must be considered hazardous and if that hazard is limited
to +_200 then we are VERY lucky.



The standards are for guidance - sometimes it is wise to exceed their
requirements.

How many designers use 8mm for Reinforced Insulation and then supply product
to Colorado?



Gregg
  -Original Message-
  From: owner-emc-p...@majordomo.ieee.org
[mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of j...@aol.com
  Sent: Tuesday, October 23, 2001 12:37 PM
  To: phopk...@ga.conklincorp.com; emc-p...@majordomo.ieee.org
  Subject: Re: TNV Circuits


  In a message dated 10/23/01, Perry Hopkins writes:




My question is; by definition, shouldn't the DSL circuits fall under the
TNV-3 and not Hazardous Voltage secondary circuit.  The major difference is
when you are determining the creepage and clearance distances.  At TNV-3 you
are allowed basic insulation between TNV-3 circuits and SELV circuits but at
the Haz Voltage Reinforced insulation is required.






  Hi Perry:

  If you have the reported 190 VDC span powering on your DSL lines, you may
well be forced into the hazardous voltage category.  In clause 2.3.1(b), UL
60950 limits TNV voltages to 60 VDC, with voltages up to 120 VDC allowed if
current limiting is included.  Clause 3.5.3 allows central supply voltages
up to 80 VDC to be declared TNV-2 under certain circumstances.  However,
voltages of 190 VDC exceed any definitions of TNV that I am aware of.

  The issue of span powering and the requisite insulation requirements
created quite a commotion a year or two ago when the Second Edition of UL
1950 was about to become mandatory.  As written, the Second Edition would
have rendered noncompliant a wide range of T1 equipment that was widely
deployed and still in production.  As I recall, the effort to bring this to
UL's attention was led by Adtran.

  I seem to recall seeing a document that was worked out between the
industry and UL to address the legacy products that used high voltage span
powering.  I do not recall the details, but if it would be helpful I can
look into it for you.  I do not know whether the agreement that was reached
for these legacy products could be applied to your situation.


  Joe Randolph
  Telecom Design Consultant
  Randolph Telecom, Inc.
  http://www.randolph-telecom.com