Re: [PSES] ESD question

[John Woodgate]

Hello, Doug. As you know, the 'spherical model' is a classic joke about 
physicists, but only half-joking because they do workas long as you 
don't 'push' the model too far.  Take a human of 80 kg who just floats, 
they seem to have a 'spherical' capacitance of 300 pF (but  I don't 
trust my arithmetic this early in the morning).


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

On 2018-06-20 00:10, Doug Smith wrote:

Hi John and the group,

Actually I was just kidding everyone. But I am going to start telling 
everyone my body is about 24 pF/ns and see what happens. I will keep 
an eye open for the men in the white coats with nets. Actually I have 
been watching for them for some time now. Just completed a run at 100 
F. Will be running in 111+ F on Thursday at the peak of the afternoon. 
Some day I will act my age.


Doug



On Tue, 19 Jun 2018 22:29:44 +0100, John Woodgate wrote:

I think the model should assume a spherical body of the relevant mass, 
which capacitance in the archaic unit 'centimetres' is equal to its 
radius in cm,  and 1 cm = 1.13 pF. With all respect to Doug, I think 
the BCI is about as scientific as BMI, which is at least a pressure 
(kg/metre-squared) of some sort. I'm not sure what pF/ns would represent.


Of course the capacitance of a spherical grandmother of any radius is 
1 nanafarad.


John Woodgate OOO-Own Opinions Only
J M Woodgate and Associateswww.woodjohn.uk
Rayleigh, Essex UK
On 2018-06-19 22:06, Doug Smith wrote:

Hi Ken and the group,

The model started out in IEC 801-2 which had a 150 Ohm, 150 pF model. 
This eventually became IEC 6000-4-2 at 330 Ohms and 150 pF. Both were 
meant to model a piece of metal in a human hand. Such a discharge is 
an order of magnitude more severe, even for a tiny piece of metal in 
one's hand, than a discharge directly from a human hand if one 
measures the radiated EMI from these events.


The R and C above were the result of many measurements on people. The 
first engineers to describe the IEC 61000-4-2 pulse as it is today, 
with the sharp peak at the start, was Michael King and David Reynolds 
back when dinosaurs roamed the earth in the last century.


There is a semiconductor device handling spec called "Human Body 
Model" using 100 pF and 1500 Ohms. But, for me, there are no good HBM 
simulators on the market as they all have metallic tips. They need a 
tip composed of material that has the same volume and surface 
resistivity as a human finger. There it goes, now no one can patent 
the idea...it is now in the public domain.


Since capacitance goes by surface area, we may need a new capacitance 
value as the population has gained weight. I propose we replace BMI 
(Body Mass Index) with the BCI (Body Capacitance Index) a combination 
of body free space capacitance in pF of a person and the number of 
nanoseconds (at one foot per nanosecond) it takes for light to go from 
head to foot. Like BCI = [body capacitance]/[body length in 
nanoseconds at the speed of light]. For me that might be about 25 
pF/ns. Some of my friends might be about 45 pF/ns.


Wow, two ideas in the same email!

Doug


On Tue, 19 Jun 2018 15:34:57 -0500, Ken Javor wrote:


What with Doug Smith being active in this sort of standard writing 
activity, I doubt it’s simply inertia.


Ken Javor
Phone: (256) 650-5261



*From: *John Woodgate 
*Date: *Tue, 19 Jun 2018 21:26:38 +0100
*To: *Ken Javor , 


*Subject: *Re: [PSES] ESD question



Probably handed down on a stone tablet in 1910 and no-one had the 
courage to challenge it yet. (;-)



John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates www.woodjohn.uk  


Rayleigh, Essex UK

On 2018-06-19 21:18, Ken Javor wrote:

ESD question Anyone out there know the origins of the 150 pF/330
ohm gun model used in EN61000-4-2 and derivative standards? It
seems it ought to be a human body model, but it isn't.

 Ken Javor
 Phone: (256) 650-5261 -
 


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Re: [PSES] ESD question

[Doug Smith]

Hi John and the group,

Actually I was just kidding everyone. But I am going to start telling everyone 
my body is about 24 pF/ns and see what happens. I will keep an eye open for the 
men in the white coats with nets. Actually I have been watching for them for 
some time now. Just completed a run at 100 F. Will be running in 111+ F on 
Thursday at the peak of the afternoon. Some day I will act my age.

Doug








On Tue, 19 Jun 2018 22:29:44 +0100, John Woodgate  wrote:


I think the model should assume a spherical body of the relevant mass, which 
capacitance in the archaic unit 'centimetres' is equal to its radius in 
cm,  and 1 cm = 1.13 pF. With all respect to Doug, I think the BCI is 
about as scientific as BMI, which is at least a pressure (kg/metre-squared) of 
some sort. I'm not sure what pF/ns would represent.  

Of course the capacitance of a spherical grandmother of any radius is 1 
nanafarad.

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

On 2018-06-19 22:06, Doug Smith wrote:

 





Hi Ken and the group,

The model started out in IEC 801-2 which had a 150 Ohm, 150 pF model. This 
eventually became IEC 6000-4-2 at 330 Ohms and 150 pF. Both were meant to model 
a piece of metal in a human hand. Such a discharge is an order of magnitude 
more severe, even for a tiny piece of metal in one's hand, than a discharge 
directly from a human hand if one measures the radiated EMI from these events.

The R and C above were the result of many measurements on people. The first 
engineers to describe the IEC 61000-4-2 pulse as it is today, with the sharp 
peak at the start, was Michael King and David Reynolds back when dinosaurs 
roamed the earth in the last century.

There is a semiconductor device handling spec called "Human Body Model" using 
100 pF and 1500 Ohms. But, for me, there are no good HBM simulators on the 
market as they all have metallic tips. They need a tip composed of material 
that has the same volume and surface resistivity as a human finger. There it 
goes, now no one can patent the idea...it is now in the public domain.

Since capacitance goes by surface area, we may need a new capacitance value as 
the population has gained weight. I propose we replace BMI (Body Mass Index) 
with the BCI (Body Capacitance Index) a combination of body free space 
capacitance in pF of a person and the number of nanoseconds (at one foot per 
nanosecond) it takes for light to go from head to foot. Like BCI = [body 
capacitance]/[body length in nanoseconds at the speed of light]. For me that 
might be about 25 pF/ns. Some of my friends might be about 45 pF/ns.

Wow, two ideas in the same email!

Doug



On Tue, 19 Jun 2018 15:34:57 -0500, Ken Javor  wrote:



What with Doug Smith being active in this sort of standard writing activity, I 
doubt it’s simply inertia.

Ken Javor
Phone: (256) 650-5261


 
From: John Woodgate 
Date: Tue, 19 Jun 2018 21:26:38 +0100
To: Ken Javor , 

Subject: Re: [PSES] ESD question

   

Probably handed down on a stone tablet in 1910 and no-one had the courage to 
challenge it yet. (;-)

 
John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates www.woodjohn.uk ;
Rayleigh, Essex UK
 
On 2018-06-19 21:18, Ken Javor wrote:
 
 

ESD question Anyone out there know the origins of the 150 pF/330 ohm gun model 
used in EN61000-4-2 and derivative standards? It seems it ought to be a human 
body model, but it isn't.
 
 Ken Javor
 Phone: (256) 650-5261 -
 
 

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

 

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

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Re: [PSES] ESD question

[Doug Smith]

Hi Chas,

I think at the time Michael King was developing the data for modern standards 
on ESD, David Pommerenke was likely just starting kindergarten. David came 
around much later, even later than the extensive work at Bell Labs I 
participated in characterizing simulators of the time. The model of the 
simulator predates David's work by many years as far as I know.

Doug








On Tue, 19 Jun 2018 21:08:16 +, "Grasso, Charles"  wrote:

  








Ken,

 

The gun model is derived from extensive research by Mike King and others (David 
Pommerenke) to derive
a pulse that reflects an ESD event from a human with an intervening metal 
object. 

 

I have copied Mike for his input. Dr Pommerenke is on the EMC blog.

 

 

Thanks

 

Charles Grasso

(w) 303-706-5467

 

 

 

 



From: Ken Javor [mailto:ken.ja...@emccompliance.com]
Sent: Tuesday, June 19, 2018 2:35 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] ESD question



 

 This message originated outside of DISH and was sent by: 
owner-emc-p...@listserv.ieee.org 

What with Doug Smith being active in this sort of standard writing activity, I 
doubt it’s simply inertia.

Ken Javor
Phone: (256) 650-5261







From: John Woodgate 
Date: Tue, 19 Jun 2018 21:26:38 +0100
To: Ken Javor , 

Subject: Re: [PSES] ESD question

   

Probably handed down on a stone tablet in 1910 and no-one had the courage to 
challenge it yet. (;-)

 
John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates www.woodjohn.uk  ;
Rayleigh, Essex UK
 
On 2018-06-19 21:18, Ken Javor wrote:
 
 


ESD question Anyone out there know the origins of the 150 pF/330 ohm gun model 
used in EN61000-4-2 and derivative standards? It seems it ought to be a human 
body model, but it isn't.
 
 Ken Javor
 Phone: (256) 650-5261 -
 
 

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

 

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

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

Website: http://www.ieee-pses.org/
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For policy questions, send mail to:
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Re: [PSES] ESD question

[Ken Javor]

This is going downhill fast but I¹m enjoying the ride!

Ken Javor
Phone: (256) 650-5261




From: John Woodgate 
Reply-To: John Woodgate 
Date: Tue, 19 Jun 2018 22:29:44 +0100
To: 
Subject: Re: [PSES] ESD question

   

I think the model should assume a spherical body of the relevant mass, which
capacitance in the archaic unit 'centimetres' is equal to its radius in cm, 
and 1 cm = 1.13 pF. With all respect to Doug, I think the BCI is about as
scientific as BMI, which is at least a pressure (kg/metre-squared) of some
sort. I'm not sure what pF/ns would represent. 
 
 

Of course the capacitance of a spherical grandmother of any radius is 1
nanafarad.
 
 
John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates www.woodjohn.uk 
Rayleigh, Essex UK
 
On 2018-06-19 22:06, Doug Smith wrote:
 
 
>   
> Hi Ken and the group,
>  
>  The model started out in IEC 801-2 which had a 150 Ohm, 150 pF model. This
> eventually became IEC 6000-4-2 at 330 Ohms and 150 pF. Both were meant to
> model a piece of metal in a human hand. Such a discharge is an order of
> magnitude more severe, even for a tiny piece of metal in one's hand, than a
> discharge directly from a human hand if one measures the radiated EMI from
> these events.
>  
>  The R and C above were the result of many measurements on people. The first
> engineers to describe the IEC 61000-4-2 pulse as it is today, with the sharp
> peak at the start, was Michael King and David Reynolds back when dinosaurs
> roamed the earth in the last century.
>  
>  There is a semiconductor device handling spec called "Human Body Model" using
> 100 pF and 1500 Ohms. But, for me, there are no good HBM simulators on the
> market as they all have metallic tips. They need a tip composed of material
> that has the same volume and surface resistivity as a human finger. There it
> goes, now no one can patent the idea...it is now in the public domain.
>  
>  Since capacitance goes by surface area, we may need a new capacitance value
> as the population has gained weight. I propose we replace BMI (Body Mass
> Index) with the BCI (Body Capacitance Index) a combination of body free space
> capacitance in pF of a person and the number of nanoseconds (at one foot per
> nanosecond) it takes for light to go from head to foot. Like BCI = [body
> capacitance]/[body length in nanoseconds at the speed of light]. For me that
> might be about 25 pF/ns. Some of my friends might be about 45 pF/ns.
>  
>  Wow, two ideas in the same email!
>  
>  Doug   
> 
>
>  
>  On Tue, 19 Jun 2018 15:34:57 -0500, Ken Javor  wrote:
>  
>  
>   What with Doug Smith being active in this sort of standard writing activity,
> I doubt it¹s simply inertia.
>  
>  Ken Javor
>  Phone: (256) 650-5261
>  
>  
>    
> 
> From: John Woodgate  
>  Date: Tue, 19 Jun 2018 21:26:38 +0100
>  To: Ken Javor 
>  , 
> 
>  Subject: Re: [PSES] ESD question
>  
>     
>  
>  Probably handed down on a stone tablet in 1910 and no-one had the courage to
> challenge it yet. (;-)
>  
>   
>  John Woodgate OOO-Own Opinions Only
>  J M Woodgate and Associates www.woodjohn.uk 
> 
>  Rayleigh, Essex UK
>   
>  On 2018-06-19 21:18, Ken Javor wrote:
>   
>    
>> ESD question Anyone out there know the origins of the 150 pF/330 ohm gun
>> model used in EN61000-4-2 and derivative standards? It seems it ought to be a
>> human body model, but it isn't.
>>   
>>   Ken Javor
>>   Phone: (256) 650-5261 -
>>  
>>   
>>  
>>  This message is from the IEEE Product Safety Engineering Society emc-pstc
>> discussion list. To post a message to the list, send your e-mail to
>>  
>>   
>>  
>>  All emc-pstc postings are archived and searchable on the web at:
>> http://www.ieee-pses.org/emc-pstc.html
>>   
>>  
>>  Attachments are not permitted but the IEEE PSES Online Communities site at
>> http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used
>> formats), large files, etc.
>>   
>>  
>>  Website: http://www.ieee-pses.org/
>>   Instructions: http://www.ieee-pses.org/list.html (including how to
>> unsubscribe) 
>>   List rules: http://www.ieee-pses.org/listrules.html
>>   
>>  
>>  For help, send mail to the list administrators:
>>   Scott Douglas  
>>   Mike Cantwell  
>>   
>>  
>>  For policy questions, send mail to:
>>   Jim Bacher  
>>   David Heald  
>>   
>  
>   
>  -
>  
> 
> This message is from the IEEE Product Safety Engineering Society emc-pstc
> discussion list. To post a message to the list, send your e-mail to
> 
>  
> 
> All emc-pstc postings are archived and sear

Re: [PSES] ESD question

[Grasso, Charles]

Ken,

The gun model is derived from extensive research by Mike King and others (David 
Pommerenke) to derive
a pulse that reflects an ESD event from a human with an intervening metal 
object.

I have copied Mike for his input. Dr Pommerenke is on the EMC blog.


Thanks

Charles Grasso
(w) 303-706-5467




From: Ken Javor [mailto:ken.ja...@emccompliance.com]
Sent: Tuesday, June 19, 2018 2:35 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] ESD question


 This message originated outside of DISH and was sent by: 
owner-emc-p...@listserv.ieee.org
What with Doug Smith being active in this sort of standard writing activity, I 
doubt it's simply inertia.

Ken Javor
Phone: (256) 650-5261



From: John Woodgate mailto:j...@woodjohn.uk>>
Date: Tue, 19 Jun 2018 21:26:38 +0100
To: Ken Javor 
mailto:ken.ja...@emccompliance.com>>, 
mailto:EMC-PSTC@LISTSERV.IEEE.ORG>>
Subject: Re: [PSES] ESD question



Probably handed down on a stone tablet in 1910 and no-one had the courage to 
challenge it yet. (;-)


John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates www.woodjohn.uk 

Rayleigh, Essex UK

On 2018-06-19 21:18, Ken Javor wrote:


ESD question Anyone out there know the origins of the 150 pF/330 ohm gun model 
used in EN61000-4-2 and derivative standards? It seems it ought to be a human 
body model, but it isn't.

 Ken Javor
 Phone: (256) 650-5261 -
 


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


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


Attachments are not permitted but the IEEE PSES Online Communities site at 
http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used 
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 Instructions: http://www.ieee-pses.org/list.html (including how to 
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 List rules: http://www.ieee-pses.org/listrules.html


For help, send mail to the list administrators:
 Scott Douglas mailto:sdoug...@ieee.org>>
 Mike Cantwell mailto:mcantw...@ieee.org>>


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



-


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David Heald mailto:dhe...@gmail.com>>

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Jim Bacher:  
David Heald: 

Re: [PSES] ESD question

[John Woodgate]

I think the model should assume a spherical body of the relevant mass, 
which capacitance in the archaic unit 'centimetres' is equal to its 
radius in cm,  and 1 cm = 1.13 pF. With all respect to Doug, I think the 
BCI is about as scientific as BMI, which is at least a pressure 
(kg/metre-squared) of some sort. I'm not sure what pF/ns would represent.


Of course the capacitance of a spherical grandmother of any radius is 1 
nanafarad.


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

On 2018-06-19 22:06, Doug Smith wrote:

Hi Ken and the group,

The model started out in IEC 801-2 which had a 150 Ohm, 150 pF model. 
This eventually became IEC 6000-4-2 at 330 Ohms and 150 pF. Both were 
meant to model a piece of metal in a human hand. Such a discharge is 
an order of magnitude more severe, even for a tiny piece of metal in 
one's hand, than a discharge directly from a human hand if one 
measures the radiated EMI from these events.


The R and C above were the result of many measurements on people. The 
first engineers to describe the IEC 61000-4-2 pulse as it is today, 
with the sharp peak at the start, was Michael King and David Reynolds 
back when dinosaurs roamed the earth in the last century.


There is a semiconductor device handling spec called "Human Body 
Model" using 100 pF and 1500 Ohms. But, for me, there are no good HBM 
simulators on the market as they all have metallic tips. They need a 
tip composed of material that has the same volume and surface 
resistivity as a human finger. There it goes, now no one can patent 
the idea...it is now in the public domain.


Since capacitance goes by surface area, we may need a new capacitance 
value as the population has gained weight. I propose we replace BMI 
(Body Mass Index) with the BCI (Body Capacitance Index) a combination 
of body free space capacitance in pF of a person and the number of 
nanoseconds (at one foot per nanosecond) it takes for light to go from 
head to foot. Like BCI = [body capacitance]/[body length in 
nanoseconds at the speed of light]. For me that might be about 25 
pF/ns. Some of my friends might be about 45 pF/ns.


Wow, two ideas in the same email!

Doug



On Tue, 19 Jun 2018 15:34:57 -0500, Ken Javor wrote:



What with Doug Smith being active in this sort of standard writing 
activity, I doubt it’s simply inertia.


Ken Javor
Phone: (256) 650-5261



*From: *John Woodgate 
*Date: *Tue, 19 Jun 2018 21:26:38 +0100
*To: *Ken Javor , 


*Subject: *Re: [PSES] ESD question



Probably handed down on a stone tablet in 1910 and no-one had the 
courage to challenge it yet. (;-)



John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates www.woodjohn.uk  


Rayleigh, Essex UK

On 2018-06-19 21:18, Ken Javor wrote:

ESD question Anyone out there know the origins of the 150 pF/330
ohm gun model used in EN61000-4-2 and derivative standards? It
seems it ought to be a human body model, but it isn't.

 Ken Javor
 Phone: (256) 650-5261 -
 


This message is from the IEEE Product Safety Engineering Society
emc-pstc discussion list. To post a message to the list, send your
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Re: [PSES] ESD question

[Doug Smith]

HI Ken and the group,

ESD testing is very definitely measuring jelly with a micometer! In my 
opinion, we are wasting time thinking about the measurement uncertainty of the 
scope, the target, the coaxial cable when the ESD simulator itself by far is 
the largest source of error as far as an EUT is concerned.

Actually, the standard is not very good. Repeatability of ESD testing is poor. 
Simulator A will pass an EUT but simulator B fails it. And vice-versa for 
another EUT.

I proposed, along with a few others in about 1995, that a di/dt spec on the 
waveform would go a long way to fix the problems. That plus radiation specs on 
the simulator would vastly improve ESD testing. But the IEC committee rejected 
the proposal as it would obsolete existing simulators (the KeyTek Mini-Zap 
would have met the proposed spec). Many other simulators had 5 GHz noise all 
over the waveform but managed to meet the spec from a "loophole" in the spec 
due to bandwidth limitations of scopes of the period.

Doug








On Tue, 19 Jun 2018 22:14:46 +0100, John Woodgate  wrote:


Yes, that's what Annex A says, but it's still a stone tablet. 'determined', 
'shown'; by whom? when?  I'm not attacking the committee, because it may 
well be impossible to do better. But we should understand what sort of 
information or data we are using. I have been known to liken most of EMC 
testing to 'measuring jelly (Jello) with a micrometer'.

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

On 2018-06-19 22:05, Ken Javor wrote:

 





Thank you!

Ken Javor
Phone: (256) 650-5261


 
From: "Schaefer, David" 
Date: Tue, 19 Jun 2018 20:56:57 +
To: Ken Javor , "EMC-PSTC@LISTSERV.IEEE.ORG" 

Conversation: [PSES] ESD question
Subject: RE: [PSES] ESD question

Ken,
 
Annex A in the 2008 edition has this to say:
 
A.7 Selection of elements for the ESD generator
A storage capacitance shall be used which is representative of the capacitance 
of the human
body. A typical value of 150 pF has been determined suitable for this purpose.
A resistance of 330 Ohms has been chosen to represent the source resistance of 
a human body
holding a metallic object such as a key or tool. It has been shown that this 
metal discharge
situation is sufficiently severe to represent all human discharges in the field.
  

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Re: [PSES] ESD question

[Ken Javor]

My purpose was solely to research the rationale (which I should have found
on my own in my 1995 copy, but didn¹t until the 2008 wording was presented).
For my immediate purpose, the official rationale suffices.

Ken Javor
Phone: (256) 650-5261



From: John Woodgate 
Reply-To: John Woodgate 
Date: Tue, 19 Jun 2018 22:14:46 +0100
To: 
Subject: Re: [PSES] ESD question

   

Yes, that's what Annex A says, but it's still a stone tablet. 'determined',
'shown'; by whom? when?  I'm not attacking the committee, because it may
well be impossible to do better. But we should understand what sort of
information or data we are using. I have been known to liken most of EMC
testing to 'measuring jelly (Jello) with a micrometer'.
 
 
John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates www.woodjohn.uk 
Rayleigh, Essex UK
 
On 2018-06-19 22:05, Ken Javor wrote:
 
 
>  Re: [PSES] ESD question Thank you!
>  
>  Ken Javor
>  Phone: (256) 650-5261
>  
>  
>  
>  
> 
> From: "Schaefer, David" 
> 
>  Date: Tue, 19 Jun 2018 20:56:57 +
>  To: Ken Javor 
>  , "EMC-PSTC@LISTSERV.IEEE.ORG"
>   
> 
>  Conversation: [PSES] ESD question
>  Subject: RE: [PSES] ESD question
>  
>  Ken, 
>   
>  Annex A in the 2008 edition has this to say:
>   
>  A.7 Selection of elements for the ESD generator
>  A storage capacitance shall be used which is representative of the
> capacitance of the human
>  body. A typical value of 150 pF has been determined suitable for this
> purpose.
>  A resistance of 330 Ohms has been chosen to represent the source resistance
> of a human body
>  holding a metallic object such as a key or tool. It has been shown that this
> metal discharge
>  situation is sufficiently severe to represent all human discharges in the
> field.
>    
>  
 
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Re: [PSES] ESD question

[Ken Javor]

What I glean from the below that wasn¹t in the other responses is that while
the measurements on human body capacity were made some time ago (when
dinosaurs roamed the earth), it might in fact be worthwhile to reexamine the
measurements, because the dinosaurs have evolved and grown larger...

:-)

Ken Javor
Phone: (256) 650-5261



From: Doug Smith 
Reply-To: 
Date: Tue, 19 Jun 2018 17:06:06 -0400
To: , 
Subject: Re: [PSES] ESD question

Hi Ken and the group,

The model started out in IEC 801-2 which had a 150 Ohm, 150 pF model. This
eventually became IEC 6000-4-2 at 330 Ohms and 150 pF. Both were meant to
model a piece of metal in a human hand. Such a discharge is an order of
magnitude more severe, even for a tiny piece of metal in one's hand, than a
discharge directly from a human hand if one measures the radiated EMI from
these events.

The R and C above were the result of many measurements on people. The first
engineers to describe the IEC 61000-4-2 pulse as it is today, with the sharp
peak at the start, was Michael King and David Reynolds back when dinosaurs
roamed the earth in the last century.

There is a semiconductor device handling spec called "Human Body Model"
using 100 pF and 1500 Ohms. But, for me, there are no good HBM simulators on
the market as they all have metallic tips. They need a tip composed of
material that has the same volume and surface resistivity as a human finger.
There it goes, now no one can patent the idea...it is now in the public
domain.

Since capacitance goes by surface area, we may need a new capacitance value
as the population has gained weight. I propose we replace BMI (Body Mass
Index) with the BCI (Body Capacitance Index) a combination of body free
space capacitance in pF of a person and the number of nanoseconds (at one
foot per nanosecond) it takes for light to go from head to foot. Like BCI =
[body capacitance]/[body length in nanoseconds at the speed of light]. For
me that might be about 25 pF/ns. Some of my friends might be about 45 pF/ns.

Wow, two ideas in the same email!

Doug 



On Tue, 19 Jun 2018 15:34:57 -0500, Ken Javor  wrote:


What with Doug Smith being active in this sort of standard writing activity,
I doubt it¹s simply inertia.

Ken Javor
Phone: (256) 650-5261


 

From: John Woodgate 
Date: Tue, 19 Jun 2018 21:26:38 +0100
To: Ken Javor , 
Subject: Re: [PSES] ESD question

   

Probably handed down on a stone tablet in 1910 and no-one had the courage to
challenge it yet. (;-)

 
John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates www.woodjohn.uk 
Rayleigh, Essex UK
 
On 2018-06-19 21:18, Ken Javor wrote:
 
 
> ESD question Anyone out there know the origins of the 150 pF/330 ohm gun model
> used in EN61000-4-2 and derivative standards? It seems it ought to be a human
> body model, but it isn't.
>  
>  Ken Javor
>  Phone: (256) 650-5261 -
>  
>  
> 
> This message is from the IEEE Product Safety Engineering Society emc-pstc
> discussion list. To post a message to the list, send your e-mail to
> 
>  
> 
> All emc-pstc postings are archived and searchable on the web at:
> http://www.ieee-pses.org/emc-pstc.html
>  
> 
> Attachments are not permitted but the IEEE PSES Online Communities site at
> http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used
> formats), large files, etc.
>  
> 
> Website: http://www.ieee-pses.org/
>  Instructions: http://www.ieee-pses.org/list.html (including how to
> unsubscribe) 
>  List rules: http://www.ieee-pses.org/listrules.html
>  
> 
> For help, send mail to the list administrators:
>  Scott Douglas 
>  Mike Cantwell 
>  
> 
> For policy questions, send mail to:
>  Jim Bacher 
>  David Heald 
>  

 
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Attachments are not 

Re: [PSES] ESD question

[John Woodgate]

Yes, that's what Annex A says, but it's still a stone tablet. 
'determined', 'shown'; by whom? when?  I'm not attacking the committee, 
because it may well be impossible to do better. But we should understand 
what sort of information or data we are using. I have been known to 
liken most of EMC testing to 'measuring jelly (Jello) with a micrometer'.


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

On 2018-06-19 22:05, Ken Javor wrote:

Re: [PSES] ESD question Thank you!

Ken Javor
Phone: (256) 650-5261




*From: *"Schaefer, David" 
*Date: *Tue, 19 Jun 2018 20:56:57 +
*To: *Ken Javor , 
"EMC-PSTC@LISTSERV.IEEE.ORG" 

*Conversation: *[PSES] ESD question
*Subject: *RE: [PSES] ESD question

Ken,

Annex A in the 2008 edition has this to say:

*A.7 Selection of elements for the ESD generator
*A storage capacitance shall be used which is representative of the 
capacitance of the human
body. A typical value of 150 pF has been determined suitable for this 
purpose.
A resistance of 330 Ohms has been chosen to represent the source 
resistance of a human body
holding a metallic object such as a key or tool. It has been shown 
that this metal discharge
situation is sufficiently severe to represent all human discharges in 
the field.





-

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Jim Bacher:  
David Heald: 

Re: [PSES] ESD question

[Doug Smith]

Hi Ken and the group,

The model started out in IEC 801-2 which had a 150 Ohm, 150 pF model. This 
eventually became IEC 6000-4-2 at 330 Ohms and 150 pF. Both were meant to model 
a piece of metal in a human hand. Such a discharge is an order of magnitude 
more severe, even for a tiny piece of metal in one's hand, than a discharge 
directly from a human hand if one measures the radiated EMI from these events.

The R and C above were the result of many measurements on people. The first 
engineers to describe the IEC 61000-4-2 pulse as it is today, with the sharp 
peak at the start, was Michael King and David Reynolds back when dinosaurs 
roamed the earth in the last century.

There is a semiconductor device handling spec called "Human Body Model" using 
100 pF and 1500 Ohms. But, for me, there are no good HBM simulators on the 
market as they all have metallic tips. They need a tip composed of material 
that has the same volume and surface resistivity as a human finger. There it 
goes, now no one can patent the idea...it is now in the public domain.

Since capacitance goes by surface area, we may need a new capacitance value as 
the population has gained weight. I propose we replace BMI (Body Mass Index) 
with the BCI (Body Capacitance Index) a combination of body free space 
capacitance in pF of a person and the number of nanoseconds (at one foot per 
nanosecond) it takes for light to go from head to foot. Like BCI = [body 
capacitance]/[body length in nanoseconds at the speed of light]. For me that 
might be about 25 pF/ns. Some of my friends might be about 45 pF/ns.

Wow, two ideas in the same email!

Doug








On Tue, 19 Jun 2018 15:34:57 -0500, Ken Javor  wrote:






What with Doug Smith being active in this sort of standard writing activity, I 
doubt it’s simply inertia.

Ken Javor
Phone: (256) 650-5261


 
From: John Woodgate 
Date: Tue, 19 Jun 2018 21:26:38 +0100
To: Ken Javor , 

Subject: Re: [PSES] ESD question

   

Probably handed down on a stone tablet in 1910 and no-one had the courage to 
challenge it yet. (;-)

 
John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates www.woodjohn.uk ;
Rayleigh, Essex UK
 
On 2018-06-19 21:18, Ken Javor wrote:
 
 

ESD question Anyone out there know the origins of the 150 pF/330 ohm gun model 
used in EN61000-4-2 and derivative standards? It seems it ought to be a human 
body model, but it isn't.
 
 Ken Javor
 Phone: (256) 650-5261 -
 
 

This message is from the IEEE Product Safety Engineering Society emc-pstc 
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Re: [PSES] ESD question

[Ken Javor]

Thank you!

Ken Javor
Phone: (256) 650-5261




From: "Schaefer, David" 
Date: Tue, 19 Jun 2018 20:56:57 +
To: Ken Javor , "EMC-PSTC@LISTSERV.IEEE.ORG"

Conversation: [PSES] ESD question
Subject: RE: [PSES] ESD question

Ken, 
 
Annex A in the 2008 edition has this to say:
 
A.7 Selection of elements for the ESD generator
A storage capacitance shall be used which is representative of the
capacitance of the human
body. A typical value of 150 pF has been determined suitable for this
purpose.
A resistance of 330 Ohms has been chosen to represent the source resistance
of a human body
holding a metallic object such as a key or tool. It has been shown that this
metal discharge
situation is sufficiently severe to represent all human discharges in the
field.
 
 
Thanks,
 
David
 
 

From: Ken Javor [mailto:ken.ja...@emccompliance.com]
Sent: Tuesday, June 19, 2018 3:35 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] ESD question
 
What with Doug Smith being active in this sort of standard writing activity,
I doubt it¹s simply inertia.

Ken Javor
Phone: (256) 650-5261



From: John Woodgate 
Date: Tue, 19 Jun 2018 21:26:38 +0100
To: Ken Javor , 
Subject: Re: [PSES] ESD question

   

Probably handed down on a stone tablet in 1910 and no-one had the courage to
challenge it yet. (;-)

 
John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates www.woodjohn.uk 

Rayleigh, Essex UK
 
On 2018-06-19 21:18, Ken Javor wrote:
 
 
> ESD question Anyone out there know the origins of the 150 pF/330 ohm gun model
> used in EN61000-4-2 and derivative standards? It seems it ought to be a human
> body model, but it isn't.
>  
>  Ken Javor
>  Phone: (256) 650-5261 -
>  
>  
> 
> This message is from the IEEE Product Safety Engineering Society emc-pstc
> discussion list. To post a message to the list, send your e-mail to
> 
>  
> 
> All emc-pstc postings are archived and searchable on the web at:
> http://www.ieee-pses.org/emc-pstc.html
>  
> 
> Attachments are not permitted but the IEEE PSES Online Communities site at
> http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used
> formats), large files, etc.
>  
> 
> Website: http://www.ieee-pses.org/
>  Instructions: http://www.ieee-pses.org/list.html (including how to
> unsubscribe) 
>  List rules: http://www.ieee-pses.org/listrules.html
>  
> 
> For help, send mail to the list administrators:
>  Scott Douglas 
>  Mike Cantwell 
>  
> 
> For policy questions, send mail to:
>  Jim Bacher 
>  David Heald 
>  

 
-

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Re: [PSES] ESD question

[John Woodgate]

The inertia in the committee that studies ESD is very large indeed. 
No-one wants to have to throw away all their test gear and buy new, and 
no-one wants to re-test and debug running products. As long as the 
current standard keeps field returns for ESD damage to an acceptable 
minimum, it won't be changed.


The question, 'Cui bono?' ought to be asked a lot in EMC committees.

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

On 2018-06-19 21:34, Ken Javor wrote:
Re: [PSES] ESD question What with Doug Smith being active in this sort 
of standard writing activity, I doubt it’s simply inertia.


Ken Javor
Phone: (256) 650-5261




*From: *John Woodgate 
*Date: *Tue, 19 Jun 2018 21:26:38 +0100
*To: *Ken Javor , 


*Subject: *Re: [PSES] ESD question



Probably handed down on a stone tablet in 1910 and no-one had the 
courage to challenge it yet. (;-)



John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates www.woodjohn.uk  


Rayleigh, Essex UK

On 2018-06-19 21:18, Ken Javor wrote:


ESD question Anyone out there know the origins of the 150 pF/330
ohm gun model used in EN61000-4-2 and derivative standards? It
seems it ought to be a human body model, but it isn't.

 Ken Javor
 Phone: (256) 650-5261 -
 


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Re: [PSES] UL Listing of Computer Keyboard

[Pete Perkins]

Brian,  I always appreciate your comments based upon your experience and your 
enthusiastic cynicism toward life.  
Altho I tried to separate the variables it appears that I did not do it 
sufficiently.  In my prior post I allowed as how the certification expenses are 
on a product or product family basis including associated certificate costs.  
The FUS, however, is based upon factory location and by similar equipment group 
(e.g. UL Efile #s); the inspection is based upon looking at something in each 
equipment group so not every product type is examined each FUS Qtly visit.  
Further the inspection time/cost is fixed so that the FUS cost to the mfgr is 
spread out over the units produced , whether a single product or several 
related products and includes the volume (not from the inspectors point of view 
but from the mfgrs bean counter point of view).  My example pointed to this 
type of scenario.  Perhaps this provides more clarification.  

:>) br,  Pete

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

503/452-1201

IEEE Life Fellow
p.perk...@ieee.org

-Original Message-
From: Brian O'Connell  
Sent: Tuesday, June 19, 2018 10:43 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] UL Listing of Computer Keyboard

FUS audit and certification and license costs are not necessarily able to be 
distributed over a larger production number; will depend on the particular 
NRTL/SCC.

For many product combinations,  there is no cost efficiency for volume or for 
factory consolidation for the respective 'regulatory' remit. The agencies will 
always find a way to structure fees and processes to extract maximum dollars 
and minimize engineering time. That is, for any given agency, invoiced line 
items will always increase, while provided services will always decrease.

Doubleplusgood. Less is more.

Brian
Senior News Reviewer of Oceania


From: Pete Perkins [mailto:0061f3f32d0c-dmarc-requ...@ieee.org]
Sent: Tuesday, June 19, 2018 8:56 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] UL Listing of Computer Keyboard

James,

   As an American I’m not privy to the inner workings of making the 
sausage called EU Directives.  However, there is a political process involved 
an all of this work and I’m sure that manufacturers and political regulators 
pushed back and forth to get to the final result for the update to the LVD.  I 
agree with your assessment that companies don’t want the extra cost of type 
approval and have prevailed at this point for this set of circumstances.  

   Somewhat related comment; since your keyboard is USB powered you 
need to understand that USB, like POE, is going to higher power delivery – 100W 
coming for USB3.  There are additional issues that need to be addressed and IEC 
62368-3 addresses power over communication cables no matter what the product 
type is; products using such comm cables will need to be assessed to ensure 
that they provide the proper protection coming and going when attached to these 
common outlet sockets.  Again, NRTL certification is appropriate for evaluating 
this equipment.  

   Finally, yes, these NRTL certifications are on a product by 
product basis; you can bunch similar models into one certification report tho.  
From experience, the FUS unit cost decreases as there is more product produced. 
 Increasing the volume of either a product model or adding more similar models 
will drive down the unit cost as the inspection time is spread over more models 
and units.  For instance for your 1K dollars/Euros or whatever, if the factory 
only produces a single unit per inspection quarter then that unit eats the 
entire cost; if the factory produces 10K units per inspection quarter then the 
unit cost is quite cheap.  

:>) br,  Pete

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

503/452-1201

IEEE Life Fellow
p.perk...@ieee.org

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Re: [PSES] ESD question

[Ken Javor]

What with Doug Smith being active in this sort of standard writing activity,
I doubt it¹s simply inertia.

Ken Javor
Phone: (256) 650-5261




From: John Woodgate 
Date: Tue, 19 Jun 2018 21:26:38 +0100
To: Ken Javor , 
Subject: Re: [PSES] ESD question

   

Probably handed down on a stone tablet in 1910 and no-one had the courage to
challenge it yet. (;-)
 
 
John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates www.woodjohn.uk 
Rayleigh, Essex UK
 
On 2018-06-19 21:18, Ken Javor wrote:
 
 
>  ESD question Anyone out there know the origins of the 150 pF/330 ohm gun
> model used in EN61000-4-2 and derivative standards? It seems it ought to be a
> human body model, but it isn't.
>  
>  Ken Javor
>  Phone: (256) 650-5261 -
>  
>  
> 
> This message is from the IEEE Product Safety Engineering Society emc-pstc
> discussion list. To post a message to the list, send your e-mail to
> 
>  
> 
> All emc-pstc postings are archived and searchable on the web at:
> http://www.ieee-pses.org/emc-pstc.html
>  
> 
> Attachments are not permitted but the IEEE PSES Online Communities site at
> http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used
> formats), large files, etc.
>  
> 
> Website: http://www.ieee-pses.org/
>  Instructions: http://www.ieee-pses.org/list.html (including how to
> unsubscribe) 
>  List rules: http://www.ieee-pses.org/listrules.html
>  
> 
> For help, send mail to the list administrators:
>  Scott Douglas 
>  Mike Cantwell 
>  
> 
> For policy questions, send mail to:
>  Jim Bacher 
>  David Heald 
>  
 
 


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Re: [PSES] ESD question

[John Woodgate]

Probably handed down on a stone tablet in 1910 and no-one had the 
courage to challenge it yet. (;-)


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

On 2018-06-19 21:18, Ken Javor wrote:
ESD question Anyone out there know the origins of the 150 pF/330 ohm 
gun model used in EN61000-4-2 and derivative standards? It seems it 
ought to be a human body model, but it isn't.


Ken Javor
Phone: (256) 650-5261 -


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[PSES] ESD question

[Ken Javor]

Anyone out there know the origins of the 150 pF/330 ohm gun model used in
EN61000-4-2 and derivative standards? It seems it ought to be a human body
model, but it isn't.

Ken Javor
Phone: (256) 650-5261

-

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Re: [PSES] Process IEC60950-1 vs. IEC60601-1

[Leo Eisner]

Agree with Brian in his YAID [Yet Another It Depends]

But if you are in the real scope of IEC 60601 series standards that also means 
you will have a regulatory submission to the likes of FDA, Health Canada, EU 
Notified Bodies, etc.  There is a lot more overhead for these regulatory 
submissions over just the 60601 series of standards.  Like needing a quality 
system that meets ISO 13485, Risk MAnagement Process per ISO 14971, Usability 
Engineering Process under IEC 62366-1 (for FDA already), IEC 62304 (software 
lifecycle process for med dvcs - includes more than real s/w, etc.).  Then you 
need to put together a much more extensive technical file / design history 
file, your production records need to be more in control, etc.

Focusing in on the IEC 60601 standards there are some significant differences 
between 60601 Series & 60950-1 

Essential Performance (not well understood still after 13 years since 3rd ed. 
out and 6 yrs since ed. 3.1 out) and Risk Management File requirements (based 
on ISO 14971 Risk Mgmt for Med Dvcs) is a heavy lift even for many in the med 
dvc industry 

There are about 70 standards in the Series plus related life cycle standards: 
such as IEC 62304 software lifecycle process for med dvcs + IEC 62366 or IEC 
62366-1 Usability Engineering Process for med dvcs (FDA already is expecting 
this version but not linked on the CB side yet and won’t be til IEC 60601-1, 
ed. 3.2 is released which likely will be sometime in 2020)

IEC 60950-1 is linked to 60601-1 currently for Means of Operator Protection 
only.  Means of Patient Protection has higher Creepage, Air Clearance and 
Dielectric limits. 

There are additional Leakage Current Tests past Earth and Touch Current related 
to Patient Leakage Limits which are much more stringent 

Most CB labs (even if not getting a CB cert & rprt) will require 60601-1, 
60601-1-6 (Usability linked to IEC 62366), IEC 60601-1-8 (Alarms, if 
applicable) and any particular standard(s) that apply to the device.

You will need to test to IEC 60601-1-2 (EMC) and at this point I would highly 
recommend doing 4th ed. (major change from 3rd ed) but will be required for all 
new submissions and change submissions to FDA & Health Canada by end of this 
year.  For EU mandated for all products (new or old products as of Jan 1 2019).

Note that IEC 62368-1, 3rd ed. ( I know in FDIS currently) is being worked on 
for inclusion into 60601-1 ed. 3.2 (I am on the ad hoc committee for this 
work).  Basically we are just starting our analysis into how we will integrate 
into IEC 60601-1 and we will keep the IEC 60950-1 references, etc. for this 
work.  I suspect when we go to 4th ed of IEC 60601-1 we may take out some of 
the IEC 60950-1 sources and text, etc.

And much more in differences between the standards.

Some additional resources around IEC 60601-1 and it’s series.

I have provided a webinar (free) on how to be successful on IEC 60601-1 
projects https://www.greenlight.guru/webinar/iec-60601-1 
 

InCompliance in June published an article I wrote about using standards  to 
keep up to date on changes to requirements 
https://incompliancemag.com/article/how-to-stay-up-to-date-on-the-ever-changing-landscape-of-the-medical-electrical-device-regulatory-world/
 


I spoke at the FDA in May at their ASCA (Accreditation Scheme for Conformity 
Assessment) Workshop from the manufacturer’s perspective related to IEC 60601 
testing at test labs and how FDA looks at test reports (usually CB Scheme 
report formats) 
https://www.fda.gov/MedicalDevices/NewsEvents/WorkshopsConferences/ucm592094.htm
 


Hope this all helps,

Leonard (Leo) Eisner, P.E.
Principal Consultant, Eisner Safety Consultants
Phone: (503) 244-6151 
Mobile: (503) 709-8328 
Email: l...@eisnersafety.com 
Website: www.EisnerSafety.com 
   
  
  
    

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Re: [PSES] UL Listing of Computer Keyboard

[Brian O'Connell]

FUS audit and certification and license costs are not necessarily able to be 
distributed over a larger production number; will depend on the particular 
NRTL/SCC.

For many product combinations,  there is no cost efficiency for volume or for 
factory consolidation for the respective 'regulatory' remit. The agencies will 
always find a way to structure fees and processes to extract maximum dollars 
and minimize engineering time. That is, for any given agency, invoiced line 
items will always increase, while provided services will always decrease.

Doubleplusgood. Less is more.

Brian
Senior News Reviewer of Oceania


From: Pete Perkins [mailto:0061f3f32d0c-dmarc-requ...@ieee.org] 
Sent: Tuesday, June 19, 2018 8:56 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] UL Listing of Computer Keyboard

James,

   As an American I’m not privy to the inner workings of making the 
sausage called EU Directives.  However, there is a political process involved 
an all of this work and I’m sure that manufacturers and political regulators 
pushed back and forth to get to the final result for the update to the LVD.  I 
agree with your assessment that companies don’t want the extra cost of type 
approval and have prevailed at this point for this set of circumstances.  

   Somewhat related comment; since your keyboard is USB powered you 
need to understand that USB, like POE, is going to higher power delivery – 100W 
coming for USB3.  There are additional issues that need to be addressed and IEC 
62368-3 addresses power over communication cables no matter what the product 
type is; products using such comm cables will need to be assessed to ensure 
that they provide the proper protection coming and going when attached to these 
common outlet sockets.  Again, NRTL certification is appropriate for evaluating 
this equipment.  

   Finally, yes, these NRTL certifications are on a product by 
product basis; you can bunch similar models into one certification report tho.  
From experience, the FUS unit cost decreases as there is more product produced. 
 Increasing the volume of either a product model or adding more similar models 
will drive down the unit cost as the inspection time is spread over more models 
and units.  For instance for your 1K dollars/Euros or whatever, if the factory 
only produces a single unit per inspection quarter then that unit eats the 
entire cost; if the factory produces 10K units per inspection quarter then the 
unit cost is quite cheap.  

:>) br,  Pete

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

503/452-1201

IEEE Life Fellow
p.perk...@ieee.org

-

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Re: [PSES] UL Listing of Computer Keyboard

[Pete Perkins]

James,

 

   As an American I’m not privy to the inner workings of making the 
sausage called EU Directives.  However, there is a political process involved 
an all of this work and I’m sure that manufacturers and political regulators 
pushed back and forth to get to the final result for the update to the LVD.  I 
agree with your assessment that companies don’t want the extra cost of type 
approval and have prevailed at this point for this set of circumstances.  

 

   Somewhat related comment; since your keyboard is USB powered you 
need to understand that USB, like POE, is going to higher power delivery – 100W 
coming for USB3.  There are additional issues that need to be addressed and IEC 
62368-3 addresses power over communication cables no matter what the product 
type is; products using such comm cables will need to be assessed to ensure 
that they provide the proper protection coming and going when attached to these 
common outlet sockets.  Again, NRTL certification is appropriate for evaluating 
this equipment.  

 

   Finally, yes, these NRTL certifications are on a product by 
product basis; you can bunch similar models into one certification report tho.  
From experience, the FUS unit cost decreases as there is more product produced. 
 Increasing the volume of either a product model or adding more similar models 
will drive down the unit cost as the inspection time is spread over more models 
and units.  For instance for your 1K dollars/Euros or whatever, if the factory 
only produces a single unit per inspection quarter then that unit eats the 
entire cost; if the factory produces 10K units per inspection quarter then the 
unit cost is quite cheap.  

 

:>) br,  Pete

 

Peter E Perkins, PE

Principal Product Safety & Regulatory Affairs Consultant

PO Box 23427

Tigard, ORe  97281-3427

 

503/452-1201

 

IEEE Life Fellow

  p.perk...@ieee.org

 

From: James Pawson (U3C)  
Sent: Tuesday, June 19, 2018 1:56 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] UL Listing of Computer Keyboard

 

Hi all,

 

Thanks very much for the illuminating replies, it’s a great help. To summarise 
(and to make sure I’ve understood):

 

*   NRTL approval legally required for selling in the USA? No.
*   NRTL / UL approval expected? Highly likely.
*   NRTL approval required for use in the workplace? Yes, not legally 
required but market expectation? Or is it a legal requirement?
*   Standard used: UL 62368-1

 

@Pete Perkins: are you saying when the LVD was recast that they tried to remove 
the lower voltage limit? Presumably this didn’t happen because companies didn’t 
want the extra workload involved with extra testing / assessment?

 

Having looked at EN 62368-1, there’s not a great deal in there that applies to 
a low power device such as a USB powered keyboard so I think it’s fair to say 
that the type approval wouldn’t take a great deal of time / cost.

 

Reading http://www.productapprovals.co.uk/ul-approval.html there appear to be 
initial and regular factory inspections associated with a NRTL listing, with 
the figure of a few thousand dollars being quoted as a typical fee for 
maintaining an NRTL mark. Does this match people’s experience?

 

If the factory already has NRTL approval for manufacturing another product, 
could one piggyback onto this approval or is it on a per product basis?

 

Thanks again

James

 

 

 

 

 

From: Pete Perkins <0061f3f32d0c-dmarc-requ...@ieee.org 
 > 
Sent: 19 June 2018 00:27
To: EMC-PSTC@LISTSERV.IEEE.ORG  
Subject: Re: [PSES] UL Listing of Computer Keyboard

 

Dave, et al,

 

   I think that you are simplifying the discussion too much.  
Certainly a wall-wart with an ELV output is not an electric shock hazard but 
that is no guarantee that any NRTL wall-wart power supply will not start a fire 
in any device which it powers; that can only be determined by inspection and 
testing.  

 

James, is your keyboard wireless?  

 

   The EU has long had an ELV exclusion for equipment under the 
LVD.  But, because of the issue raised here, there was an effort to remove that 
in the last update to the LVD which, unfortunately, failed.  So a partial fix 
is that if a device has a radio in it must meet the Radio Equipment Directive 
and that RED Directive encompasses all of the hazards such that the electrical 
safety standards used under the LVD now apply except that the ELV exclusion is 
eliminated; a step in the right direction, I believe.  (So the LVD is not 
invoked of itself when meeting the RED directive but the appropriate safety 
standard is.)  

   Now it is obvious why Rich Nute’s Bluetooth mouse bears 
appropriate safety marks.  

 

:>) br,  Pete

 

Peter E Perkins, PE

Principal Product Safety & Regulatory Affairs Consultant

PO Box 

Re: [PSES] UL Listing of Computer Keyboard

[Ted Eckert]

NRTL approval is not a legal requirement to sell a product in the United 
States. There is no national legal requirement for many types of consumer 
products. Many jurisdictions have adopted NFPA 70, the National Electrical 
Code, which requires products either to be Listed by an NRTL or to be approved 
by the local inspector. This creates a de facto NRTL requirement for most 
permanently connected products. Inspections typically only occur during 
construction or renovation.

NRTL approval is expected for line-voltage products. Many large retailers won’t 
carry products unless they have NRTL approval. However, there are plenty of 
on-line and physical stores that don’t have NRTL requirements for the products 
they sell.

OSHA under the Department of Labor sets requirements for the workplace and OSHA 
does mandate NRTL approvals. OSHA actually manages the NRTL program as noted by 
one of the earlier commenters.

The standard for a keyboard depends on how it is used. I had a colleague that 
worked on 60601 approval for a keyboard used in medical applications. For the 
office, it would be UL 60950-1 or UL 62368-1, with the former standard being 
withdrawn in late 2020 if I recall correctly. The application in the U.S. is 
different than in Europe. Products certified to UL 60950-1 can continue to 
carry the certification mark after the date of withdrawal of the standard. 
Another date may be set further in the future when UL 60950-1 products would 
then need to be recertified to UL 62368-1.

Keyboards that are USB powered or use alkaline batteries technically fall under 
the OSHA requirements, but are generally considered low enough power that it is 
extremely unlikely that an inspector would require them to be NRTL approved.

If a keyboard is included in the retail package with an NRTL Listed computer, 
the NRTL may require the keyboard to be a Listed Accessory. Many NRTLs will 
require all included electrical accessories to be Listed if they are included 
in the same SKU with an NRTL Listed product.

Ted Eckert
Microsoft Corporation
The opinions expressed are my own and do not necessarily reflect those of my 
employer.



From: James Pawson (U3C) 
Sent: Tuesday, June 19, 2018 1:56 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] UL Listing of Computer Keyboard

Hi all,

Thanks very much for the illuminating replies, it’s a great help. To summarise 
(and to make sure I’ve understood):


  *   NRTL approval legally required for selling in the USA? No.
  *   NRTL / UL approval expected? Highly likely.
  *   NRTL approval required for use in the workplace? Yes, not legally 
required but market expectation? Or is it a legal requirement?
  *   Standard used: UL 62368-1

@Pete Perkins: are you saying when the LVD was recast that they tried to remove 
the lower voltage limit? Presumably this didn’t happen because companies didn’t 
want the extra workload involved with extra testing / assessment?

Having looked at EN 62368-1, there’s not a great deal in there that applies to 
a low power device such as a USB powered keyboard so I think it’s fair to say 
that the type approval wouldn’t take a great deal of time / cost.

Reading 
http://www.productapprovals.co.uk/ul-approval.html
 there appear to be initial and regular factory inspections associated with a 
NRTL listing, with the figure of a few thousand dollars being quoted as a 
typical fee for maintaining an NRTL mark. Does this match people’s experience?

If the factory already has NRTL approval for manufacturing another product, 
could one piggyback onto this approval or is it on a per product basis?

Thanks again
James

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Re: [PSES] UL Listing of Computer Keyboard

[James Pawson (U3C)]

Hi all,

 

Thanks very much for the illuminating replies, it’s a great help. To summarise 
(and to make sure I’ve understood):

 

*   NRTL approval legally required for selling in the USA? No.
*   NRTL / UL approval expected? Highly likely.
*   NRTL approval required for use in the workplace? Yes, not legally 
required but market expectation? Or is it a legal requirement?
*   Standard used: UL 62368-1

 

@Pete Perkins: are you saying when the LVD was recast that they tried to remove 
the lower voltage limit? Presumably this didn’t happen because companies didn’t 
want the extra workload involved with extra testing / assessment?

 

Having looked at EN 62368-1, there’s not a great deal in there that applies to 
a low power device such as a USB powered keyboard so I think it’s fair to say 
that the type approval wouldn’t take a great deal of time / cost.

 

Reading http://www.productapprovals.co.uk/ul-approval.html there appear to be 
initial and regular factory inspections associated with a NRTL listing, with 
the figure of a few thousand dollars being quoted as a typical fee for 
maintaining an NRTL mark. Does this match people’s experience?

 

If the factory already has NRTL approval for manufacturing another product, 
could one piggyback onto this approval or is it on a per product basis?

 

Thanks again

James

 

 

 

 

 

From: Pete Perkins <0061f3f32d0c-dmarc-requ...@ieee.org> 
Sent: 19 June 2018 00:27
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] UL Listing of Computer Keyboard

 

Dave, et al,

 

   I think that you are simplifying the discussion too much.  
Certainly a wall-wart with an ELV output is not an electric shock hazard but 
that is no guarantee that any NRTL wall-wart power supply will not start a fire 
in any device which it powers; that can only be determined by inspection and 
testing.  

 

James, is your keyboard wireless?  

 

   The EU has long had an ELV exclusion for equipment under the 
LVD.  But, because of the issue raised here, there was an effort to remove that 
in the last update to the LVD which, unfortunately, failed.  So a partial fix 
is that if a device has a radio in it must meet the Radio Equipment Directive 
and that RED Directive encompasses all of the hazards such that the electrical 
safety standards used under the LVD now apply except that the ELV exclusion is 
eliminated; a step in the right direction, I believe.  (So the LVD is not 
invoked of itself when meeting the RED directive but the appropriate safety 
standard is.)  

   Now it is obvious why Rich Nute’s Bluetooth mouse bears 
appropriate safety marks.  

 

:>) br,  Pete

 

Peter E Perkins, PE

Principal Product Safety & Regulatory Affairs Consultant

PO Box 23427

Tigard, ORe  97281-3427

 

503/452-1201

 

IEEE Life Fellow

  p.perk...@ieee.org

 

From: Nyffenegger, Dave mailto:dave.nyffeneg...@bhemail.com> > 
Sent: Monday, June 18, 2018 1:15 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG  
Subject: Re: [PSES] UL Listing of Computer Keyboard

 

This is generally true however there are plenty of examples of products for 
sale as well as those used in the workplace that are simple in nature and/or 
non-hazardous and do not carry an NRTL mark.  For example, the stapler on your 
desk or even the phone on your desk.  If it plugs into a power outlet in the 
wall it needs NRTL.  A computer keyboard could have one but is it really 
needed?  The main reason a lot of OEMs use wall warts is they NRTL certify the 
wall wart (or more likely source one from another OEM) but not the product that 
it supplies power to as it doesn’t need it.

 

-Dave

 

From: Monrad Monsen [mailto:monrad.mon...@oracle.com] 
Sent: Monday, June 18, 2018 12:02 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG  
Subject: Re: [PSES] UL Listing of Computer Keyboard

 

Hi James, 

Please note that the OSHA Nationally Recognized Test Laboratory (NRTL) will 
verify your product to UL62368-1 standard (based on international IEC62368-1). 
The OSHA regulation mandates that employers provide a safe working environment 
for employees (and local building codes support those requirements) plus retail 
stores don’t want to be sued for selling unsafe products if someone is harmed 
or property damaged, so neither employers nor retail stores will buy or re-sell 
a product that does not have a NRTL approval. As Darren notes, NRTL labs are 
not just UL but also CSA, TUV Rheinland, TUV Sud, ETL (Intertek), Nemko, etc. A 
full listing is at the web page below:

https://www.osha.gov/dts/otpca/nrtl/nrtllist.html

 

Hope this helps.

Monrad 

 

Sent from my iPhone


On Jun 18, 2018, at 3:03 AM, CATHERINE PEARSON 
<0b0df63784fb-dmarc-requ...@ieee.org 
 > wrote:

Hi James,

 

Is UL listing mandatory for IT accessories like keyboards? 
No any NRTL certifica