Re: Near Field Versus Far Field

[Ravinder Ajmani/San Jose/IBM]

Several excellent ideas have been put forward on this phenomenon.  Here is
my $.02 worth on the subject.
I have often been able to reduce the far-field emissions, based on the
reduction in near-field emissions.  The important thing is to co-relate the
far-field and near-field emissions, by comparing their frequency spectrums.
It is possible that the 400 MHz clock you worked on with near field probe
may not be the real culprit.  Another trace may be coupling the 400 MHz
clock noise to some cable, or one of the other signals, which is driven by
the 400 MHz clock, may be the real source.

Regards, Ravinder
PCB Development and Design Department
IBM Corporation - Storage Systems Division
Email: ajm...@us.ibm.com
***
Always do right.  This will gratify some people and astonish the rest.
 Mark Twain



marti...@appliedbiosystems.com@ieee.org on 09/14/2000 10:07:36 AM

Please respond to marti...@appliedbiosystems.com

Sent by:  owner-emc-p...@ieee.org


To:   emc-p...@majordomo.ieee.org
cc:
Subject:  Near Field Versus Far Field






I am having a difficult time answering the following question for a
non-technical person.  Hopefully, someone can put the answer into a
language
that a non-technical person can understand.

We have a 400 MHz clock and are failing radiated emissions at 10 meters by
10 dB
at 400 MHz.  We bring the product back to our lab and start making
modifications
on the clock circuit and taking measurements with a near field probe.  With
these modifications and measuring with a near field probe, we realize a 10
dB
reduction in emissions at 400 MHz.  Why would we not see the same reduction
when
taking the product back to a 10 meter site?

Your help is appreciated.

Regards

Joe Martin
marti...@appliedbiosystems.com



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Re: PCB fuse trace

[Jim Freeman]

Hi Peter,
The simple metal tubes are a vacumn and the metal isn't surrounded
by volatile material as it is in the PCN trace.

Jim Freeman


Peter Tarver wrote:

>
>
> Jim -
>
> Except for when a high breaking capacity fuse is needed, arc
> extinguishing fillers, like sand, are not generally necessary.  I
> would also expect that such a fuse would not be in a primary circuit,
> where the US safety standard expects a fuse to see 10kA for miniature
> fuses.  Even most of these fuses (again, in the US) don't use arc
> extinguishing fillers, but are simple glass tubes with metal ferrules
> (the 1" by 1-1/4" miniature fuses, and even several varieties of 5mm
> by 20mm fuses).
>
> The above is based on my experience testing fuses for about 4 years,
> during my tenure at UL.
>
> Regards,
>
> Peter L. Tarver, PE
> ptar...@nortelnetworks.com
>
> -Original Message-
> From: Jim Freeman
>
> In all of this discussion, no one has mentioned the possibility of
> fire from blowing a PCB trace fuse. I know that there are flame
> retardants in the PCB material that protect to a certain flashpoint
> but to rely on that mechanism for fire prevention is a bit far
> fetched. From my limite experience with fuses, there is generally a
> large structure that is enclosed in sand to prevent a fire from
> spreading.
>
> Jim Freeman
>
> Peter Tarver wrote:
>
> My experience with safety agencies is they do not want to rely on
> traces opening to act as fuses and no standards have been developed,
> that I am aware of, to address this issue.  Fuses certification gets
> involved in the metallic alloys used, to the fraction of a percent,
> the conductor size, additional construction features, such as heat
> sinking elements for time delay characteristics, tension loading for
> fast action, blah, blah, blah.
>
> Most of these issues are far too difficult to control for pwb traces,
> especially considering the etching processes don't lend themselves to
> the level of control necessary to be a reliable fuse of specific
> ratings.  Additionally, the heat sinking from pwb layout of one
> product to another or varying copper thicknesses in a product line,
> adding or subtracting ground planes for emc, the variability of
> soldering processes and location/thermal capacity of components on the
> pwb make this seem far too cumbersome to want to work with.
>
> BTW, this is a very different world from "repeated twice, same result"
> single-fault testing, where a pwb trace opens.
> Regards,
> Peter L. Tarver, PE
> ptar...@nortelnetworks.com
>
> -Original Message-
> From: Matsuda, Ken [mailto:matsu...@curtisinst.com]
> Sent: Thursday, September 14, 2000 7:02 AM
> To: emc-p...@ieee.org
> Subject: PCB fuse trace
>
> I was wondering if anyone knew a standard for the US, Canada, and
> Europe
> that covers PCB board traces that can be used as fuses?
>
>
> Thanks for the help,
> Ken
>

Re: Immunity measurement uncertainty

[brent . dewitt]

You might try the IEEE EMC Symposium archives.  There have been lots of papers
over the years.  I co-authored a paper with Dan Hoolihan on radiated immunity
uncertainty for the 1997 symposium.

Regards,

Brent DeWitt
Datex-Ohmeda
Louisville, CO







Leslie Bai  on 09/14/2000 02:23:33 PM

Please respond to Leslie Bai 

To:   "IEEE EMC-PSTC \(E-mail\)" 
cc:(bcc: Brent Dewitt/US/D-O)

Subject:  Immunity measurement uncertainty





Hello, members,

Is there anyone who can direct me to somewhere I can
find the method to derive the Immunity Test
Uncertainties, e.g. ESD, RI, EFT/B, Surge, etc.

Thanks,
Leslie

__
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RE: Near Field Versus Far Field

[Tudor, Allen]

Consider how the reflected wave from the ground plane at the 10m site might
add or subtract to the incident wave depending on frequency and antenna
height.  Also, the near-field probe measurement is taken in the near-field
(obviously) while the antenna at the 10m sight is in the far field.  Also,
your results with the near-field probe will depend on probe orientation and
distance held from the product.

-Original Message-
From: Bronaugh, Edwin [mailto:edwin.brona...@icn.siemens.com]
Sent: Thursday, September 14, 2000 5:10 PM
To: 'marti...@appliedbiosystems.com'; emc-p...@majordomo.ieee.org
Subject: RE: Near Field Versus Far Field



Mr. Martin, have you thought about the fact that the near-field probe does
not integrate the whole radiation sphere from your product?  On the 10 m
site, your antenna sees radiation components from all parts of the EUT,
including any cables; while your near-field probe in the lab cannot pick all
of these up at the same relative levels and phases as does the antenna on
the OATS.  This may not be your problem, but in my opinion, it invites
investigation.

Regards, EdB

-Original Message-
From: marti...@appliedbiosystems.com
[mailto:marti...@appliedbiosystems.com]
Sent: Thursday, September 14, 2000 12:08 PM
To: emc-p...@majordomo.ieee.org
Subject: Near Field Versus Far Field





I am having a difficult time answering the following question for a
non-technical person.  Hopefully, someone can put the answer into a language
that a non-technical person can understand.

We have a 400 MHz clock and are failing radiated emissions at 10 meters by
10 dB
at 400 MHz.  We bring the product back to our lab and start making
modifications
on the clock circuit and taking measurements with a near field probe.  With
these modifications and measuring with a near field probe, we realize a 10
dB
reduction in emissions at 400 MHz.  Why would we not see the same reduction
when
taking the product back to a 10 meter site?

Your help is appreciated.

Regards

Joe Martin
marti...@appliedbiosystems.com



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RE: Enclosure Material & Immunity

[Tudor, Allen]

Henry Ott's book "Noise Reduction Techniques in Electronic Systems, Second
Edition" provides good insight into your question.  The ISBN # is
0-471-85068-3.  From chapter 6, I quote the following passages:

With respect to magnetic fields: "High permeability materials are most
useful as magnetic field shields at frequencies below 10 kHz."

With respect to electric and magnetic fields and plane waves:  "At high
frequencies (above 10 MHz), absorption loss predominates, and any solid
shield thick enough to be practical provides more than adequate shielding
for most applications...As a practical matter, the intrinsic shielding
effectiveness of the material is of less concern than the leakage through
seams, joints, and holes."

He also shows how to compute shielding effectiveness of various materials
and thicknesses.  I am sure others would agree that this book is well worth
your investment.

-Original Message-
From: Dick Grobner [mailto:dick.grob...@medgraph.com]
Sent: Thursday, September 14, 2000 10:22 AM
To: IEEE EMC-PSTC E-Mail Forum (E-mail)
Subject: Enclosure Material & Immunity



Good Day Forum Members
I have just been posed with a question here at work and I have no immediate
answer. Someone asked if an electronic enclosure constructed of stainless
steel is in any way more superior (or equivalent too) against EMI/RFI (ESD,
radiated RF, Magnetic, etc.) over one constructed of steel (zinc plated). In
the past all of our enclosure have been constructed of steel or aluminum and
plated accordingly. I do not have much in the line of resources on this
subject so any input from the forum would be appreciated!! Provide me with
your experiences, good or bad!

Thanks (in advance)  

Dick Grobner
Compliance Engineering
Medical Graphics Corporation
350 Oak Grove Parkway
St Paul, MN 55127
651-766-3395
651-766-3389 (fax)
dick.grob...@medgraph.com


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RE: Immunity measurement uncertainty

[Mike Hopkins]

Don't know about the others, but the ESD Association has done some work on
ESD uncertainties. I don't know if it's published yet (I don't think so) but
there is a meeting in Anaheim on Sunday the 23rd. I have some drafts, but
need to see if they are the final ones and if I can broadcast the info
yet..

Best Regards,

Mike Hopkins

-Original Message-
From: Leslie Bai [mailto:leslie_...@yahoo.com]
Sent: Thursday, September 14, 2000 4:24 PM
To: IEEE EMC-PSTC (E-mail)
Subject: Immunity measurement uncertainty 



Hello, members,

Is there anyone who can direct me to somewhere I can
find the method to derive the Immunity Test
Uncertainties, e.g. ESD, RI, EFT/B, Surge, etc.

Thanks,
Leslie

__
Do You Yahoo!?
Yahoo! Mail - Free email you can access from anywhere!
http://mail.yahoo.com/

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RE: Near Field Versus Far Field

[Bronaugh, Edwin]

Mr. Martin, have you thought about the fact that the near-field probe does
not integrate the whole radiation sphere from your product?  On the 10 m
site, your antenna sees radiation components from all parts of the EUT,
including any cables; while your near-field probe in the lab cannot pick all
of these up at the same relative levels and phases as does the antenna on
the OATS.  This may not be your problem, but in my opinion, it invites
investigation.

Regards, EdB

-Original Message-
From: marti...@appliedbiosystems.com
[mailto:marti...@appliedbiosystems.com]
Sent: Thursday, September 14, 2000 12:08 PM
To: emc-p...@majordomo.ieee.org
Subject: Near Field Versus Far Field





I am having a difficult time answering the following question for a
non-technical person.  Hopefully, someone can put the answer into a language
that a non-technical person can understand.

We have a 400 MHz clock and are failing radiated emissions at 10 meters by
10 dB
at 400 MHz.  We bring the product back to our lab and start making
modifications
on the clock circuit and taking measurements with a near field probe.  With
these modifications and measuring with a near field probe, we realize a 10
dB
reduction in emissions at 400 MHz.  Why would we not see the same reduction
when
taking the product back to a 10 meter site?

Your help is appreciated.

Regards

Joe Martin
marti...@appliedbiosystems.com



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Immunity measurement uncertainty

[Leslie Bai]

Hello, members,

Is there anyone who can direct me to somewhere I can
find the method to derive the Immunity Test
Uncertainties, e.g. ESD, RI, EFT/B, Surge, etc.

Thanks,
Leslie

__
Do You Yahoo!?
Yahoo! Mail - Free email you can access from anywhere!
http://mail.yahoo.com/

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RE: PCB fuse trace

[Peter Tarver]

Jim -

Except for when a high breaking capacity fuse is needed, arc extinguishing
fillers, like sand, are not generally necessary.  I would also expect that
such a fuse would not be in a primary circuit, where the US safety standard
expects a fuse to see 10kA for miniature fuses.  Even most of these fuses
(again, in the US) don't use arc extinguishing fillers, but are simple glass
tubes with metal ferrules (the 1" by 1-1/4" miniature fuses, and even
several varieties of 5mm by 20mm fuses).

The above is based on my experience testing fuses for about 4 years, during
my tenure at UL.

Regards,

Peter L. Tarver, PE
ptar...@nortelnetworks.com


-Original Message-
From: Jim Freeman


In all of this discussion, no one has mentioned the possibility of fire from
blowing a PCB trace fuse. I know that there are flame retardants in the PCB
material that protect to a certain flashpoint but to rely on that mechanism
for fire prevention is a bit far fetched. From my limite experience with
fuses, there is generally a large structure that is enclosed in sand to
prevent a fire from spreading. 
Jim Freeman 
  
Peter Tarver wrote: 
  
My experience with safety agencies is they do not want to rely on traces
opening to act as fuses and no standards have been developed, that I am
aware of, to address this issue.  Fuses certification gets involved in the
metallic alloys used, to the fraction of a percent, the conductor size,
additional construction features, such as heat sinking elements for time
delay characteristics, tension loading for fast action, blah, blah, blah. 
Most of these issues are far too difficult to control for pwb traces,
especially considering the etching processes don't lend themselves to  the
level of control necessary to be a reliable fuse of specific ratings.
Additionally, the heat sinking from pwb layout of one product to another or
varying copper thicknesses in a product line, adding or subtracting ground
planes for emc, the variability of soldering processes and location/thermal
capacity of components on the pwb make this seem far too cumbersome to want
to work with. 
BTW, this is a very different world from "repeated twice, same result"
single-fault testing, where a pwb trace opens. 
Regards, 
Peter L. Tarver, PE 
ptar...@nortelnetworks.com 

-Original Message- 
From: Matsuda, Ken [mailto:matsu...@curtisinst.com] 
Sent: Thursday, September 14, 2000 7:02 AM 
To: emc-p...@ieee.org 
Subject: PCB fuse trace 
  
I was wondering if anyone knew a standard for the US, Canada, and Europe 
that covers PCB board traces that can be used as fuses? 
  
  
Thanks for the help, 
Ken 
 

RE: Near Field Versus Far Field

[William D'Orazio]

Joe,

Let me try this one,
The near field is composed of a sum of terms 1/r, 1/r^2, etc. and the far
field is only composed of the 1/r term.  If your 10dB reduction was solely
due to a reduction in the higher order terms, 1/r^2 etc, then in the far
field no reduction will have taken place.

I hope this helps, 


William D'Orazio
CAE Electronics Ltd.
Electrical System Designer

Phone: (514) 341-2000 (X4555)
Fax: (514)340-5552
Email: dora...@cae.ca


-Original Message-
From: marti...@appliedbiosystems.com
[mailto:marti...@appliedbiosystems.com]
Sent: Thursday, September 14, 2000 1:08 PM
To: emc-p...@majordomo.ieee.org
Subject: Near Field Versus Far Field





I am having a difficult time answering the following question for a
non-technical person.  Hopefully, someone can put the answer into a language
that a non-technical person can understand.

We have a 400 MHz clock and are failing radiated emissions at 10 meters by
10 dB
at 400 MHz.  We bring the product back to our lab and start making
modifications
on the clock circuit and taking measurements with a near field probe.  With
these modifications and measuring with a near field probe, we realize a 10
dB
reduction in emissions at 400 MHz.  Why would we not see the same reduction
when
taking the product back to a 10 meter site?

Your help is appreciated.

Regards

Joe Martin
marti...@appliedbiosystems.com



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Re: PCB fuse trace

[Jim Freeman]

In all of this discussion, no one has mentioned the possibility of fire
from blowing a PCB trace fuse. I know that there are flame retardants in
the PCB material that protect to a certain flashpoint but to rely on
that mechanism for fire prevention is a bit far fetched. From my limite
experience with fuses, there is generally a large structure that is
enclosed in sand to prevent a fire from spreading.

Jim Freeman


Peter Tarver wrote:

>
>
> My experience with safety agencies is they do not want to rely on
> traces opening to act as fuses and no standards have been developed,
> that I am aware of, to address this issue.  Fuses certification gets
> involved in the metallic alloys used, to the fraction of a percent,
> the conductor size, additional construction features, such as heat
> sinking elements for time delay characteristics, tension loading for
> fast action, blah, blah, blah.
>
> Most of these issues are far too difficult to control for pwb traces,
> especially considering the etching processes don't lend themselves to
> the level of control necessary to be a reliable fuse of specific
> ratings.  Additionally, the heat sinking from pwb layout of one
> product to another or varying copper thicknesses in a product line,
> adding or subtracting ground planes for emc, the variability of
> soldering processes and location/thermal capacity of components on the
> pwb make this seem far too cumbersome to want to work with.
>
> BTW, this is a very different world from "repeated twice, same result"
> single-fault testing, where a pwb trace opens.
>
> Regards,
>
> Peter L. Tarver, PE
> ptar...@nortelnetworks.com
>
> -Original Message-
> From: Matsuda, Ken [mailto:matsu...@curtisinst.com]
> Sent: Thursday, September 14, 2000 7:02 AM
> To: emc-p...@ieee.org
> Subject: PCB fuse trace
>
>
> I was wondering if anyone knew a standard for the US, Canada, and
> Europe
> that covers PCB board traces that can be used as fuses?
>
>
>
> Thanks for the help,
>
> Ken
>
> ---
> This message is from the IEEE EMC Society Product Safety
> Technical Committee emc-pstc discussion list.
>
> To cancel your subscription, send mail to:
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> with the single line:
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>
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>  Michael Garretson:pstc_ad...@garretson.org
>
> For policy questions, send mail to:
>  Richard Nute:   ri...@ieee.org
>

RE: Enclosure Material & Immunity

[Marko Radojicic]

Dick,

A metallurgist once told me that Steel becomes Stainless due to a very thin
oxide which forms on the exterior layer. This oxide is insulative hence RF
bonding to it is somewhat more tricky. 

Note that Zinc passivated chromate may also be insulative so the problem is
not much different.

All other EM properties will be so similar as to not really make any
practical difference.

Marko Radojicic
email: ma...@caspiannetworks.com
phone: 408/382-5206
fax: tbd



-Original Message-
From: Dick Grobner [mailto:dick.grob...@medgraph.com]
Sent: Thursday, September 14, 2000 7:22 AM
To: IEEE EMC-PSTC E-Mail Forum (E-mail)
Subject: Enclosure Material & Immunity



Good Day Forum Members
I have just been posed with a question here at work and I have no immediate
answer. Someone asked if an electronic enclosure constructed of stainless
steel is in any way more superior (or equivalent too) against EMI/RFI (ESD,
radiated RF, Magnetic, etc.) over one constructed of steel (zinc plated). In
the past all of our enclosure have been constructed of steel or aluminum and
plated accordingly. I do not have much in the line of resources on this
subject so any input from the forum would be appreciated!! Provide me with
your experiences, good or bad!

Thanks (in advance)  

Dick Grobner
Compliance Engineering
Medical Graphics Corporation
350 Oak Grove Parkway
St Paul, MN 55127
651-766-3395
651-766-3389 (fax)
dick.grob...@medgraph.com


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RE: Homologations: Hong Kong / China Central Office Telecom Equipment

[georgea]

Jeff,

I have noticed the following sequence of events relative to country
certifications:

1.  No particular standards cited.
2.  Compliance with IEC 60950 stipulated, but no certification required.
3.  Certification required, but often based on CB Certificate alone.
4.  Certification required, but based on full CB Test Report and review.
5.  Addition of cited EMC standard, but without certification.
6.  EMC certification to standard(s) required.
7.  EMC test data required to be taken by in-country lab.
8.  Acceptance of "outside" EMC test data.

This is not a complete list of the possible evolutionary steps toward
country certifications.  Regulated EMC is new for China, so we are at
step 7.  I suspect that within a year or two, the SAIQ/CCIB will accept
EMC data taken by outside "qualified" labs.  Not long ago, all PCs and
peripherals had to be tested by the FCC for Class B compliance.  Imagine
the problems overseas vendors had with this.  Now this can be a self-
declaration.

Moral:  Be patient.  Every country has the right to impose whatever rules
and certification processes they deem necessary to ensure meeting their
safety and EMC objectives.  However, simplified acceptance procedures
come slowly through trust in manufacturers, and in the test labs of other
countries.

George




jwiseman%printronix@interlock.lexmark.com on 09/14/2000 01:18:57 PM

To:   George_Alspaugh/Lex/Lexmark@LEXMARK,
  emc-pstc%majordomo.ieee@interlock.lexmark.com
cc:(bcc: George Alspaugh/Lex/Lexmark)
Subject:  RE: Homologations: Hong Kong / China Central Office Telecom Equip ment



George did a good job explaining, but I am currently going through the CCIB
process myself. The thing I have found most inconvenient is that they now
require the EMC testing be done in country. They will use your current
reports only for reference. I know that some labs are trying to bring
testing outside of the PRC but with little success.

Josh

-Original Message-
From: geor...@lexmark.com [mailto:geor...@lexmark.com]
Sent: Thursday, September 14, 2000 6:48 AM
To: emc-p...@majordomo.ieee.org
Subject: Homologations: Hong Kong / China Central Office Telecom
Equipment

Jeff,

I am not familiar with telecom requirements, however, we do market our
printers
in
these locations.  Here are some things I think I know regarding generic ITE.

I am unaware of any safety/EMC certification requirements in Hong Kong.
Note
that
Hong Kong is now officially part of the People's Republic of China, but
operates
a
bit "apart" from mainland PRC.

The IEC listed CB reviewing body for the PRC is the CCEE, which has the
authority
to issue the Great Wall mark based on compliance to GB4943-1995 (IEC 60950
in
Chinese).  However, the CCEE mark is primarily required for electrical
equipment
made in China for sale in China, i.e. an internal safety mark..

All imported ITE must obtain the CCIB certification and mark to GB4943-1995
and
GB9254-1998 (EMC, CISPR 22).  A CB Test Report is accepted and preferred,
but
China labs perform the EMC tests for CCIB.  A key requirement is an initial
factory
inspection by SAIQ/CCIB personnel.  Depending on the location of your
factory,
this can be a schedule problem as they cannot afford the time to fly to the
U.S.
for
a single inspection.  Our factory was one of seven being inspected in 1998.

There are some other peripheral requirements for consumer ITE, e.g. user
manual
in simplified Chinese.  The PRC does not wish to be "westernized", and
prefers
that
packaging, documentation, etc. be in Chinese.

I hope this helps.

George Alspaugh
Lexmark International Inc.

-- Forwarded by George Alspaugh/Lex/Lexmark on
09/14/2000
09:34 AM ---

jcollins%ciena@interlock.lexmark.com on 09/14/2000 08:44:44 AM

Please respond to jcollins%ciena@interlock.lexmark.com

To:   emc-pstc%ieee@interlock.lexmark.com
cc:(bcc: George Alspaugh/Lex/Lexmark)
Subject:  Homologations: Hong Kong / China Central Office Telecom Equipment




Group,

Any experiences with getting Central Office Telecom equipment (ITE) into
Hong Kong and China?

CB Scheme to IEC 60950 should address product safety.  What about EMC? Has
the Great Wall Mark (China's version of CE Mark) been implemented?

What about environmental management issues Who would be the equivalent
to the RBOC's in Hong Kong and China???


Thanks in advance,

Jeffrey Collins
MTS, Principal Compliance Engineer
Ciena Core Switching Division
jcoll...@ciena.com
www.ciena.com


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 Ric

RE: Homologations: Hong Kong / China Central Office Telecom Equip ment

[Joshua Wiseman]

George did a good job explaining, but I am currently going through the CCIB
process myself. The thing I have found most inconvenient is that they now
require the EMC testing be done in country. They will use your current
reports only for reference. I know that some labs are trying to bring
testing outside of the PRC but with little success.

Josh

-Original Message-
From: geor...@lexmark.com [mailto:geor...@lexmark.com]
Sent: Thursday, September 14, 2000 6:48 AM
To: emc-p...@majordomo.ieee.org
Subject: Homologations: Hong Kong / China Central Office Telecom
Equipment



Jeff,

I am not familiar with telecom requirements, however, we do market our
printers
in
these locations.  Here are some things I think I know regarding generic ITE.

I am unaware of any safety/EMC certification requirements in Hong Kong.
Note
that
Hong Kong is now officially part of the People's Republic of China, but
operates
a
bit "apart" from mainland PRC.

The IEC listed CB reviewing body for the PRC is the CCEE, which has the
authority
to issue the Great Wall mark based on compliance to GB4943-1995 (IEC 60950
in
Chinese).  However, the CCEE mark is primarily required for electrical
equipment
made in China for sale in China, i.e. an internal safety mark..

All imported ITE must obtain the CCIB certification and mark to GB4943-1995
and
GB9254-1998 (EMC, CISPR 22).  A CB Test Report is accepted and preferred,
but
China labs perform the EMC tests for CCIB.  A key requirement is an initial
factory
inspection by SAIQ/CCIB personnel.  Depending on the location of your
factory,
this can be a schedule problem as they cannot afford the time to fly to the
U.S.
for
a single inspection.  Our factory was one of seven being inspected in 1998.

There are some other peripheral requirements for consumer ITE, e.g. user
manual
in simplified Chinese.  The PRC does not wish to be "westernized", and
prefers
that
packaging, documentation, etc. be in Chinese.

I hope this helps.

George Alspaugh
Lexmark International Inc.

-- Forwarded by George Alspaugh/Lex/Lexmark on
09/14/2000
09:34 AM ---

jcollins%ciena@interlock.lexmark.com on 09/14/2000 08:44:44 AM

Please respond to jcollins%ciena@interlock.lexmark.com

To:   emc-pstc%ieee@interlock.lexmark.com
cc:(bcc: George Alspaugh/Lex/Lexmark)
Subject:  Homologations: Hong Kong / China Central Office Telecom Equipment




Group,

Any experiences with getting Central Office Telecom equipment (ITE) into
Hong Kong and China?

CB Scheme to IEC 60950 should address product safety.  What about EMC? Has
the Great Wall Mark (China's version of CE Mark) been implemented?

What about environmental management issues Who would be the equivalent
to the RBOC's in Hong Kong and China???


Thanks in advance,

Jeffrey Collins
MTS, Principal Compliance Engineer
Ciena Core Switching Division
jcoll...@ciena.com
www.ciena.com


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RE: PCB fuse trace

[JENKINS, JEFF]

In addition, there is a concern about where the particles of metal from the
blasted trace will end up, or where the curled up trace will go.  This may
compromise required insulation.  As Peter points out, this may be difficult
to repeat twice with the same result.
 
Regards,
 
Jeff Jenkins
Regulatory Compliance Engineer
Advanced Energy Industries, Inc.
Fort Collins, CO  USA
 
Opinions expressed are my own and are not necessarily shared by Advanced
Energy Industries, Inc. or its affiliates.

-Original Message-
From: Peter Tarver [mailto:ptar...@nortelnetworks.com]
Sent: Thursday, September 14, 2000 9:40 AM
To: Matsuda, Ken; emc-p...@ieee.org
Subject: RE: PCB fuse trace



My experience with safety agencies is they do not want to rely on traces
opening to act as fuses and no standards have been developed, that I am
aware of, to address this issue.  Fuses certification gets involved in the
metallic alloys used, to the fraction of a percent, the conductor size,
additional construction features, such as heat sinking elements for time
delay characteristics, tension loading for fast action, blah, blah, blah.

Most of these issues are far too difficult to control for pwb traces,
especially considering the etching processes don't lend themselves to  the
level of control necessary to be a reliable fuse of specific ratings.
Additionally, the heat sinking from pwb layout of one product to another or
varying copper thicknesses in a product line, adding or subtracting ground
planes for emc, the variability of soldering processes and location/thermal
capacity of components on the pwb make this seem far too cumbersome to want
to work with.

BTW, this is a very different world from "repeated twice, same result"
single-fault testing, where a pwb trace opens. 

Regards, 

Peter L. Tarver, PE 
ptar...@nortelnetworks.com 


-Original Message- 
From: Matsuda, Ken [ mailto:matsu...@curtisinst.com
 ] 
Sent: Thursday, September 14, 2000 7:02 AM 
To: emc-p...@ieee.org 
Subject: PCB fuse trace 



I was wondering if anyone knew a standard for the US, Canada, and Europe 
that covers PCB board traces that can be used as fuses?  
  
  
  
Thanks for the help, 
  
Ken 

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Near Field Versus Far Field

[MartinJP]

I am having a difficult time answering the following question for a
non-technical person.  Hopefully, someone can put the answer into a language
that a non-technical person can understand.

We have a 400 MHz clock and are failing radiated emissions at 10 meters by 10 dB
at 400 MHz.  We bring the product back to our lab and start making modifications
on the clock circuit and taking measurements with a near field probe.  With
these modifications and measuring with a near field probe, we realize a 10 dB
reduction in emissions at 400 MHz.  Why would we not see the same reduction when
taking the product back to a 10 meter site?

Your help is appreciated.

Regards

Joe Martin
marti...@appliedbiosystems.com



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RE: Homologations: Hong Kong / China Central Office Telecom Equip ment

[George Sparacino]

Hello Jeff,

I've attached some info that I received from UL a few weeks ago.. It
addresses both, safety & EMC issues for China.  Give it a read and discuss
any further with Sam at UL.

Check out this tradeport webpage. It gives some info relating to China's MII
telecom licensing system.

http://www.tradeport.org/ts/countries/china/mrr/mark0207.html

Tradeports' Starting page for Country specific info can be found at:
http://www.tradeport.org/ts/countries/


Also, attached (below) is a hypertext copy of "Detailed Rules and Procedures
for the Implementation of the Safety License System of Import Commodities"
published by the State Administration of Import and Export Commodity
Inspection of the People's Republic of China. (..Whew, what a mouthful!)..
It gives an overview of every step in the process from submitting the
application, type testing to factory follow-up procedures. It's a good
guideline.
http://www.ccibkor.com/ccib/j_ccibing.htm


I hope some of this helps you..
George

-Original Message-
From: Collins, Jeffrey [mailto:jcoll...@ciena.com]
Sent: Thursday, September 14, 2000 8:45 AM
To: emc-p...@ieee.org
Subject: Homologations: Hong Kong / China Central Office Telecom
Equipment



Group,

Any experiences with getting Central Office Telecom equipment (ITE) into
Hong Kong and China?

CB Scheme to IEC 60950 should address product safety.  What about EMC? Has
the Great Wall Mark (China's version of CE Mark) been implemented?

What about environmental management issues Who would be the equivalent
to the RBOC's in Hong Kong and China???


Thanks in advance,

Jeffrey Collins 
MTS, Principal Compliance Engineer
Ciena Core Switching Division
jcoll...@ciena.com
www.ciena.com


---
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 Richard Nute:   ri...@ieee.org


--- Begin Message ---

Dear George,

Attached are the information relative to CCIB Safety Mark and CCEE Mark in
China for your reference.

(See attached file: ULCHINASafety Mark ITE SERVICE.doc)(See attached file:
ULCHINA iec65 SAFETY MARK SERVICE1.doc)

Shoud you desire further information relative to the submittral, please
feel free to contact us.

Best Regards,



Sam K. Yuan
Staff Engineer
International Compliance Services
Underwriters Laboratories Inc.
1285 Walt Whitman Road
Melville, NY 11747-3081
Tel: 631-271-6200, Ext. 22717
Fax: 631-439-6071
E-mail: sam.k.y...@us.ul.com
Web address: www.ul.com
(See attached file: ULCHINASafety Mark ITE SERVICE.doc)
(See attached file: ULCHINA iec65 SAFETY MARK SERVICE1.doc)
@@

*  Internet E-mail Confidentiality Disclaimer **

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 delete the e-mail and any attachments
and notify Underwriters Laboratories Inc. at
e-mail_disclai...@us.ul.com.

UL does not accept liability for any errors, omissions, corruption
or virus in the contents of this message or any attachments that
arise as a result of e-mail transmission.
**



ULCHINASafety Mark ITE SERVICE.doc
Description: Microsoft Word 4


ULCHINA iec65 SAFETY MARK SERVICE1.doc
Description: Microsoft Word 4
--- End Message ---

RE: PCB fuse trace

[Peter Tarver]

My experience with safety agencies is they do not want to rely on traces
opening to act as fuses and no standards have been developed, that I am
aware of, to address this issue.  Fuses certification gets involved in the
metallic alloys used, to the fraction of a percent, the conductor size,
additional construction features, such as heat sinking elements for time
delay characteristics, tension loading for fast action, blah, blah, blah.

Most of these issues are far too difficult to control for pwb traces,
especially considering the etching processes don't lend themselves to  the
level of control necessary to be a reliable fuse of specific ratings.
Additionally, the heat sinking from pwb layout of one product to another or
varying copper thicknesses in a product line, adding or subtracting ground
planes for emc, the variability of soldering processes and location/thermal
capacity of components on the pwb make this seem far too cumbersome to want
to work with.

BTW, this is a very different world from "repeated twice, same result"
single-fault testing, where a pwb trace opens.

Regards,

Peter L. Tarver, PE
ptar...@nortelnetworks.com


-Original Message-
From: Matsuda, Ken [mailto:matsu...@curtisinst.com]
Sent: Thursday, September 14, 2000 7:02 AM
To: emc-p...@ieee.org
Subject: PCB fuse trace



I was wondering if anyone knew a standard for the US, Canada, and Europe
that covers PCB board traces that can be used as fuses?  
 
 
 
Thanks for the help,
 
Ken

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Re: Requirements for Israel

[Peter Merguerian]

Chris Hello,

1. First, you or importer needs to get in touch with the Israel Ministry of
Industry and Trade to see if you could get exemptions for your products
from being tested at SII (Standards Institution of Israel).

2. If products need to be tested by SII, then a CB Test Report needs to be
reviewed. SII would have to conduct the Israeli deviations (normally safety
instructions and markings in Hebrew, Israeli plug and some other monor
items). EMC is also required in Israel. An EMC Report from an accredited
lab must be reviewed.

3. SII cost for getting approval based on a CB Test Report and an EMC Test
Report could be up to $1000. Cost for full testing could be in the up to
$3000 depending on the product.

If you need additional help, please contact me.

Best Regards



At 09:35 12/09/2000 +0100, Colgan, Chris wrote:
>
>Does anyone know of any mandatory safety or EMC requirements for consumer
>audio/video products in Israel?  Is third party testing and marking of
>products required?
>
>If I had a product that had been tested to IEC60065 with a CB Certificate
>and Test Report, would additional testing and cost be involved?
>
>Thanks in anticipation.
>
>Regards
>
>Chris Colgan
>EMC & Safety
>TAG McLaren Audio Ltd
>
>mailto:chris.col...@tagmclarenaudio.com
>
>=
>Authorised on 09/12/00 at 09:33:28; code 37f48bf32007B969.
>
>
>**  
>   Please visit us at www.tagmclarenaudio.com
>**
>
>The contents of this E-mail are confidential and for the exclusive
>use of the intended recipient. If you receive this E-mail in error,
>please delete it from your system immediately and notify us either
>by E-mail, telephone or fax. You  should not  copy, forward or 
>otherwise disclose the content of the E-mail.
>
>TAG McLaren Audio Ltd
>The Summit, 11 Latham Road
>Huntingdon, Cambs, PE29 6ZU
>Telephone : 01480 415600 (+44 1480 415600)
>Facsimile : 01480 52159 (+44 1480 52159)
>
>**  
>   Please visit us at www.tagmclarenaudio.com
>**
>
>---
>This message is from the IEEE EMC Society Product Safety
>Technical Committee emc-pstc discussion list.
>
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>with the single line:
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>
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> Michael Garretson:pstc_ad...@garretson.org
>
>For policy questions, send mail to:
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>
>
Peter Merguerian
Managing Director
Product Testing Division
I.T.L. (Product Testing) Ltd.
Hacharoshet 26, POB 211
Or Yehuda 60251, Israel

Tel: 972-3-5339022 Fax: 972-3-5339019
e-mail: pmerguer...@itl.co.il
website: http://www.itl.co.il 

TO LEARN ABOUT AUSTRALIAN AND NEW ZEALAND REQUIREMENTS, CONTACT ME AT THE
EARLIEST STAGES OF YOUR DESIGN; REQUIREMENTS CAN BE TRICKY!






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RE: Homologations: Hong Kong / China Central Office Telecom Equip ment

[John Juhasz]

Contact Hong Kong Telecom's CPE Evaluation group. They have the
'specification checklist'
required for you to get approval. 
You fill out the checklist with all supporting documentation (any test
reports that you have
i.e. that you used to get approval in the UK for instance) and submit. After
they 
review the checklist, HKT may/may not ask for a sample. (That's the way it
was when I did telecom equipment 2 years ago)

Unfortunately I do not have the contact name/number handy.

Regards,

John Juhasz
Fiber Options
Bohemia, NY

-Original Message-
From: Collins, Jeffrey [mailto:jcoll...@ciena.com]
Sent: Thursday, September 14, 2000 8:45 AM
To: emc-p...@ieee.org
Subject: Homologations: Hong Kong / China Central Office Telecom
Equipment



Group,

Any experiences with getting Central Office Telecom equipment (ITE) into
Hong Kong and China?

CB Scheme to IEC 60950 should address product safety.  What about EMC? Has
the Great Wall Mark (China's version of CE Mark) been implemented?

What about environmental management issues Who would be the equivalent
to the RBOC's in Hong Kong and China???


Thanks in advance,

Jeffrey Collins 
MTS, Principal Compliance Engineer
Ciena Core Switching Division
jcoll...@ciena.com
www.ciena.com


---
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Need Test Lab set up to test for ETS 300 342-1 (Mobile phone ancillary equipment)

[Robert Macy]

Does anyone know labs set up to measure mobile phone ancillary equipment?
located in northern California area?  Specifically Silicon Valley, San Jose
area.

Just need to test for radiated susceptibility at 3 V/m of a hands free
headset equipment when attached to a cell phone.

Yes, any chamber can do it, but I need a lab that has done it, knows how to
do it, and won't take 2 weeks to set it up.

- Robert -

  Robert A. Macy, PEm...@california.com
   408 286 3985  fx 408 297 9121
   AJM International Electronics Consultants
   619 North First St,   San Jose, CA  95112

PS:  Please copy me at   robert-m...@sybersay.com



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RE: Using fuse to protect wire undersized for load?

[Kazimier Gawrzyjal]

Lauren,
 
To add to Peter's comments below, another relevant factor might be the
required observation of termination temperatures and conductor ampacity and
therefore selection per NEC art. 110-14(c).  Without knowing more of the
product nature or implementation, the requirement may yet add further
argument to increasing conductor size beyond 2/0.
 
My 2 cents and not that of my employer.
 
Kaz Gawrzyjal , P. Eng.
Sr. Product Safety Engineer 
-- 
Sanmina Canada ULC 
Wireless Development Centre 
2924 11 Street NE   
Calgary, Alberta
Canada, T2E 7L7 
tel:403-769-4805 (ESN 758) 
fax:403-769-4813 (ESN 758) 
e-mail:  calgary...@aol.com  ,
k...@nortelnetworks.com   

 

 

-Original Message-
From: Tarver, Peter [SC1:9031:EXCH] 
Sent: Wednesday, September 13, 2000 5:02 PM
To: emc-p...@ieee.org
Subject: RE: Using fuse to protect wire undersized for load?



Lauren - 

I'm not familiar with NFPA79, so I'll answer only with regard to NFPA70 (the
US NEC). 

The 125% issue in the NEC is for two items:  attachment plugs sizing and
circuit breaker sizing (1/1.25 = 0.80), both relative to load current.
Attachment plugs for equipment that contain motors must be rated for not
less than 125% of the steady state operating current.  General purpose
circuit breakers need to be sized at 80% of steady state operating current
for all branch circuits, unless marked for 100% load rating when used as a
switch for lighting circuits (IIRC, this marking is "SWD").

Fuses, on the other hand, are useable up to 100% of their marked rating. 

Wiring need must be sized according to the applicable load current and
overcurrent protection provided according to the wire size and load current.

The above, of course, can be used outside these ratings, if under
engineering supervision and acceptable to the Authority Having Jurisdiction.
Use at lesser currents than rated is just fine for wiring, fuses, circuit
breakers and attachment plugs.

It's difficult to comment further, without knowing more detail about the
product, since speculation can get far afield from your specific case.

BTW, I hope your client is aware of Sections 400-7 and 400-8 of the NEC, as
well as the notes to Table 400-5(b).  I would have normally expected to use
the tables in Article 310 for this.

Regards, 

Peter L. Tarver, PE 
ptar...@nortelnetworks.com 


-Original Message- 
From: Crane, Lauren 


Colleagues, 

I have an internal client who is proposing a design. In this design, a 
resistive heating load is being supplied by conductors that are far below 
the 125% of load recommended/required by the NEC or NFPA-79 (ref 1994 sect 
15.5.3). The client argues that it is okay that the supply conductors are 
far below because they are fused at a level that will protect them. 

.26 ohm load 
driven at 120 volts max 

Full Load Amps calculates to 462 amps. 125% = 577 amps. 60degC wire size 
should be 700 mcm per NFPA-79 1994 table 11. 

Client proposes using 2/0 90degC wire because drive circuit is an SCR 
controller fused to 50 amps feeding a 4:1 step down transformer. They 
rationalized max current (given 50A fuses) is 200 amps on the secondary. 2/0

90degC wire is rated to 300 amps per NEC table 400-5b. 

It seems clear to me that the codes say the wire should be sized to the 
load. But the codes don't seem to say that wires SHOULD NOT be sized to 
thier over current protection (regardless of the load). 

Does anyone have a pro or con rational for undersizing the conductors to a 
load provided they are protected correctly by a fuse or breaker? 

Thanks in advance.  

Lauren Crane (my own opinions, not my employeer's) 
*   Product Design Safety & Compliance Manager 
*   Ion Beam and Thermal Processing Systems 
*   Axcelis Technologies Inc. 
*   108 Cherry Hill Dr. 
*   Beverly, MA  01915 
*   978.921-9745   lauren.cr...@axcelis.com 


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Hong Kong/China

[georgea]

Jeff,

I forgot to reference a few possibly helpful websites, each of which can be
linked to from www.safetylink.com

CB Scheme  www.cbscheme.org
SAIQ   http://www.ciq.gov.cn/doc/english/law1.htm
SAIQ   http://www.ciq.gov.cn/doc/english/index.htm


George



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Enclosure Material & Immunity

[Dick Grobner]

Good Day Forum Members
I have just been posed with a question here at work and I have no immediate
answer. Someone asked if an electronic enclosure constructed of stainless
steel is in any way more superior (or equivalent too) against EMI/RFI (ESD,
radiated RF, Magnetic, etc.) over one constructed of steel (zinc plated). In
the past all of our enclosure have been constructed of steel or aluminum and
plated accordingly. I do not have much in the line of resources on this
subject so any input from the forum would be appreciated!! Provide me with
your experiences, good or bad!

Thanks (in advance)  

Dick Grobner
Compliance Engineering
Medical Graphics Corporation
350 Oak Grove Parkway
St Paul, MN 55127
651-766-3395
651-766-3389 (fax)
dick.grob...@medgraph.com


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PCB fuse trace

[Matsuda, Ken]

I was wondering if anyone knew a standard for the US, Canada, and Europe
that covers PCB board traces that can be used as fuses?  
 
 
 
Thanks for the help,
 
Ken

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Homologations: Hong Kong / China Central Office Telecom Equipment

[georgea]

Jeff,

I am not familiar with telecom requirements, however, we do market our printers
in
these locations.  Here are some things I think I know regarding generic ITE.

I am unaware of any safety/EMC certification requirements in Hong Kong.  Note
that
Hong Kong is now officially part of the People's Republic of China, but operates
a
bit "apart" from mainland PRC.

The IEC listed CB reviewing body for the PRC is the CCEE, which has the
authority
to issue the Great Wall mark based on compliance to GB4943-1995 (IEC 60950 in
Chinese).  However, the CCEE mark is primarily required for electrical equipment
made in China for sale in China, i.e. an internal safety mark..

All imported ITE must obtain the CCIB certification and mark to GB4943-1995 and
GB9254-1998 (EMC, CISPR 22).  A CB Test Report is accepted and preferred, but
China labs perform the EMC tests for CCIB.  A key requirement is an initial
factory
inspection by SAIQ/CCIB personnel.  Depending on the location of your factory,
this can be a schedule problem as they cannot afford the time to fly to the U.S.
for
a single inspection.  Our factory was one of seven being inspected in 1998.

There are some other peripheral requirements for consumer ITE, e.g. user manual
in simplified Chinese.  The PRC does not wish to be "westernized", and prefers
that
packaging, documentation, etc. be in Chinese.

I hope this helps.

George Alspaugh
Lexmark International Inc.

-- Forwarded by George Alspaugh/Lex/Lexmark on 09/14/2000
09:34 AM ---

jcollins%ciena@interlock.lexmark.com on 09/14/2000 08:44:44 AM

Please respond to jcollins%ciena@interlock.lexmark.com

To:   emc-pstc%ieee@interlock.lexmark.com
cc:(bcc: George Alspaugh/Lex/Lexmark)
Subject:  Homologations: Hong Kong / China Central Office Telecom Equipment




Group,

Any experiences with getting Central Office Telecom equipment (ITE) into
Hong Kong and China?

CB Scheme to IEC 60950 should address product safety.  What about EMC? Has
the Great Wall Mark (China's version of CE Mark) been implemented?

What about environmental management issues Who would be the equivalent
to the RBOC's in Hong Kong and China???


Thanks in advance,

Jeffrey Collins
MTS, Principal Compliance Engineer
Ciena Core Switching Division
jcoll...@ciena.com
www.ciena.com


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Re:RE: Using fuse to protect wire undersized for load?

[Jim Bacher]

forwarding for daniel.sic...@marconi.com


Reply Separator
Subject:RE: Using fuse to protect wire undersized for load?
Author: daniel.sic...@marconi.com
List-Post: emc-pstc@listserv.ieee.org
Date:   9/14/00 9:28 AM




The way I understand it  they used a  4:1 step down transformer between the
input supply and the
0.26 ohm load.  The SCR based circuit is there to chopped the input waveform
feeded to the transformer
allowing to modulate the actual loading of the circuit.

Now we have 120V divide by 4 which is 30V apply to the 0.26ohm load giving
115.4A into the load.  This is
the worst case load current.  It thus seems that a 300A rated cable will meet
the 125% load requirement.

The modulation introduces by the SCR based circuit will only reduce the voltage
appearing across the load
and will just reduce the amount of current draw by the 0.26ohm load.


Opinion express here are my own and do not necessarily reflect those of my
employer.



Daniel Sicard
Compliance Engineer / Ingénieur Certification
Marconi Communications - Optical Network Corp
Tel: 514-685-1737 Ext. 4631  Fax: 514-822-4077
E-mail: mailto:daniel.sic...@marconi.com
Web: http://www.marconi.com






Jim Eichner  on 09/13/2000 04:34:28 PM

Please respond to Jim Eichner 

To:   "'EMC-PSTC - forum'" 
cc:(bcc: Daniel Sicard/MAIN/MC1)

Subject:  RE: Using fuse to protect wire undersized for load?





Either I'm missing something, or you won't be able to run the load, so code
issues are a moot point.

You point out the "equivalent" fusing is 200A and you have a 462A load.  You
will blow the fuse as soon as you power up, every time!

In the general case, you are right:  the code does not consider basing your
wire size on your fuse size.  At least not in that order.  It tells you the
wire ampacity has to be 125% of the continuous load, and the fuse or breaker
has to be the next size up from that ampacity.


Regards,

Jim Eichner
Sr. Regulatory Compliance Engineer
Xantrex Technology Inc., Mobile Markets
jim.eich...@xantrex.com
Any opinions expressed are those of my invisible friend, who really exists.
Honest.



-Original Message-
From: Crane, Lauren [mailto:lauren.cr...@axcelis.com]
Sent: Wednesday, September 13, 2000 1:00 PM
To: emc-p...@ieee.org
Subject: Using fuse to protect wire undersized for load?



Colleagues,

I have an internal client who is proposing a design. In this design, a
resistive heating load is being supplied by conductors that are far below
the 125% of load recommended/required by the NEC or NFPA-79 (ref 1994 sect
15.5.3). The client argues that it is okay that the supply conductors are
far below because they are fused at a level that will protect them.

.26 ohm load
driven at 120 volts max

Full Load Amps calculates to 462 amps. 125% = 577 amps. 60degC wire size
should be 700 mcm per NFPA-79 1994 table 11.

Client proposes using 2/0 90degC wire because drive circuit is an SCR
controller fused to 50 amps feeding a 4:1 step down transformer. They
rationalized max current (given 50A fuses) is 200 amps on the secondary. 2/0
90degC wire is rated to 300 amps per NEC table 400-5b.

It seems clear to me that the codes say the wire should be sized to the
load. But the codes don't seem to say that wires SHOULD NOT be sized to
thier over current protection (regardless of the load).

Does anyone have a pro or con rational for undersizing the conductors to a
load provided they are protected correctly by a fuse or breaker?

Thanks in advance.

Lauren Crane (my own opinions, not my employeer's)
*Product Design Safety & Compliance Manager
*Ion Beam and Thermal Processing Systems
*Axcelis Technologies Inc.
*108 Cherry Hill Dr.
*Beverly, MA  01915
*978.921-9745   lauren.cr...@axcelis.com




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Sept. 8, 2000 Conformity-Update Now Available

[Glen Dash]

Conformity-Update for the week ending Sept. 8, 2000 is now available
at:

http://www.conformity-update.com

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RE: Summary - PC's & Class B..

[George Sparacino]

Hello Group,
 
 I have been asked (privately) to post the replies that I recieved privately
regarding this subject to the group. I am glad to do so.. sorry that I
didn't think of it first.  Here you go.

Best Regards,
George



 

--- Begin Message ---

Hello Geroge

We have tested several products with different PCs.Our result is that the
HP Vectra is the best up to know. Dell has some good product too.

Best Regards

Dieter Baldamus





George Sparacino @ieee.org on
09/11/2000 09:43:58 AM

Please respond to George Sparacino 

Sent by:  owner-emc-p...@ieee.org


To:   emc-p...@ieee.org
cc:

Subject:  PC's & Class B..




Hello All,

I will be buying a new PC for EMI/EMC testing. Can anyone suggest a mfgr. /
model that is (truely) Class B compliant?

Thanks,
George



--- End Message ---
--- Begin Message ---


George,

We do Class B rarely, but last April we used a Dell XPS-T450 model CPU with
Dell
828FI monitor to retest a GPIB interface card for Class B CISPR/FCC at 10
meters.  The highest radiated emission recorded was 2.6 dB below the limit
at
214.8 MHz vertical mode.  The test configuration included an Panasonic P630B
parallel printer, keyboard, mouse, and a serial modem.  Conducted margin was
4.9
dB at 183 kHz.

We have the local contract lab run Class B FCC/DOC since we haven't
attempted
yet to seek a NVLAP on our own 10 meter site; more than 99% of our testing
is
Class A.

If you buy a Dell, don't try to pick up a used one more than a few months
old.
Dell had a radiated emission problem with one of their power supplies about
a
year ago.

Best Regards,
Eric Lifsey




Please respond to George Sparacino 

To:   emc-p...@ieee.org
cc:(bcc: Eric Lifsey/AUS/NIC)

Subject:  PC's & Class B..



Hello All,

I will be buying a new PC for EMI/EMC testing. Can anyone suggest a mfgr. /
model that is (truely) Class B compliant?


Thanks,
George







--- End Message ---
--- Begin Message ---
George,
I think you are going to hear from many folks this morning. The short
course here is to buy it with a stipulation that says if it doesn't pass you
going to bring it back. Many big name vendors have systems that have
problems by the time you see them. Could be because of the shipping and
vibration of the enclosure cover, or the peripherals you are using with it
not being compatible etc, but you might have to go through a few to find
what you need.
I have tried this with HP, IBM, and Compaq and I am very sure that they
run the tests and run them appropriately, but I still have run into
problems, but I would start there.
Another recommendation is that if you don't have the test facilities at
your place you may want to see if your test vendor will store the unit for
you and buy a second system. Shipping this things around is very hard from
and EMC performance perspective.
Gary

-Original Message-
From: George Sparacino [mailto:george.sparac...@bostonacoustics.com]
Sent: Monday, September 11, 2000 6:44 AM
To: emc-p...@ieee.org
Subject: PC's & Class B..



Hello All, 

I will be buying a new PC for EMI/EMC testing. Can anyone suggest a mfgr. /
model that is (truely) Class B compliant? 


Thanks, 
George 

--- End Message ---
--- Begin Message ---
George,
 
I have had great results with a Gateway tower. Mine is only a 200MHz CPU but
the chassis is built like a bomb shelter. Even the EMC labs I deal with were
suitably impressed.
 
ejc

-Original Message-
From: George Sparacino [mailto:george.sparac...@bostonacoustics.com]
Sent: Monday, September 11, 2000 6:44 AM
To: emc-p...@ieee.org
Subject: PC's & Class B..



Hello All, 

I will be buying a new PC for EMI/EMC testing. Can anyone suggest a mfgr. /
model that is (truely) Class B compliant? 


Thanks, 
George 
--- End Message ---
--- Begin Message ---
George, I just bought a HP Vectra.  The PC is OK, but it's monitor is
marginal. 
I understand the bigger the monitor the better the shielding, as they can
charge
more for the monitor. 

Jim

Jim Bacher,  Senior Engineer
Paxar - Monarch
email:jim_bac...@monarch.com
voice:1-937-865-2020
fax:1-937-865-2048


Reply Separator
Subject:PC's & Class B..
Author: George Sparacino 
List-Post: emc-pstc@listserv.ieee.org
Date:   9/11/00 9:43 AM

Hello All,

I will be buying a new PC for EMI/EMC testing. Can anyone suggest a mfgr. /
model that is (truely) Class B compliant?


Thanks,
George
--- End Message ---
--- Begin Message ---
In my test lab days it seemed the Compaq and Dell PC cases were the tightest
built.
 


Michael Sundstrom 
Nokia Mobile Phones, PCC 
EMC Technician 
cube  4E : 390B 
phone: 972-374-1462 
mobile: 817-917-5021 
michael.sundst...@nokia.com 
amateur call:  KB5UKT 

 

-Original Message-
From: EXT George Sparacino [mailto:george.sparac...@bostonacoustics.com]
Sent: Monday, September 11, 2000 8:44 AM
To: emc-p...@ieee.org
Subject: PC's & Class B..



Hello All, 

I will be buying a new PC for EMI/EMC testing. Can anyone sugges

Homologations: Hong Kong / China Central Office Telecom Equipment

[Collins, Jeffrey]

Group,

Any experiences with getting Central Office Telecom equipment (ITE) into
Hong Kong and China?

CB Scheme to IEC 60950 should address product safety.  What about EMC? Has
the Great Wall Mark (China's version of CE Mark) been implemented?

What about environmental management issues Who would be the equivalent
to the RBOC's in Hong Kong and China???


Thanks in advance,

Jeffrey Collins 
MTS, Principal Compliance Engineer
Ciena Core Switching Division
jcoll...@ciena.com
www.ciena.com


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Re:RE: Using fuse to protect wire undersized for load?

[Jim Bacher]

forwarding for geoff.lis...@motion-media.com

Reply Separator
Subject:RE: Using fuse to protect wire undersized for load?
Author: Geoff Lister 
List-Post: emc-pstc@listserv.ieee.org
Date:   9/14/00 10:37 AM

Lauren,
I am not familiar with high current fuses, but I would
expect their behaviour to be similar to those of lower
value.

A 50 Amp fuse is designed so that in normal service it
will never blow at 50 amps. To allow for production spreads,
most of the specs permit a fuse to withstand a continuous
current of between 150% & 170% of their rating. I believe that UL248
permits a fuse to carry 200% rated current for up to
100 seconds before blowing.

This would translate, in your application to a continuous current
of up to 340 Amps, and 400 amps for up to 100 seconds. I am not
familiar with the wire specifications that you mention, but it does
look as though a thicker wire would be required.

Regards,

Geoff Lister (geoff.lis...@motion-media.com)
Senior Engineer
Motion Media Technology Ltd.
Horton Hall, Horton, Bristol, BS37 6QN, UK
Voice direct  +44 (0) 1454 338561
Voice switchboard +44 (0) 1454 313444
Fax   +44 (0) 1454 313678
http://www.motion-media.com 

-Original Message-
From: Crane, Lauren [mailto:lauren.cr...@axcelis.com]
Sent: 13 September 2000 21:00
To: emc-p...@ieee.org
Subject: Using fuse to protect wire undersized for load?



Colleagues, 

I have an internal client who is proposing a design. In this design, a
resistive heating load is being supplied by conductors that are far below
the 125% of load recommended/required by the NEC or NFPA-79 (ref 1994 sect
15.5.3). The client argues that it is okay that the supply conductors are
far below because they are fused at a level that will protect them. 

.26 ohm load
driven at 120 volts max

Full Load Amps calculates to 462 amps. 125% = 577 amps. 60degC wire size
should be 700 mcm per NFPA-79 1994 table 11. 

Client proposes using 2/0 90degC wire because drive circuit is an SCR
controller fused to 50 amps feeding a 4:1 step down transformer. They
rationalized max current (given 50A fuses) is 200 amps on the secondary. 2/0
90degC wire is rated to 300 amps per NEC table 400-5b. 

It seems clear to me that the codes say the wire should be sized to the
load. But the codes don't seem to say that wires SHOULD NOT be sized to
thier over current protection (regardless of the load).

Does anyone have a pro or con rational for undersizing the conductors to a
load provided they are protected correctly by a fuse or breaker?

Thanks in advance.  

Lauren Crane (my own opinions, not my employeer's)
*   Product Design Safety & Compliance Manager
*   Ion Beam and Thermal Processing Systems
*   Axcelis Technologies Inc. 
*   108 Cherry Hill Dr. 
*   Beverly, MA  01915
*   978.921-9745   lauren.cr...@axcelis.com



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 Richard Nute:   ri...@ieee.org

RE: RTTE Radio Verification

[martin]

Sam,

The assumption in the approval of a product for sale in the EU is that,   
if a manufacturer affixes a CE mark to a product and issues the DoC then,   
he is effectively saying to the authorities that he takes responsibility   
for the compliance of the product, including the conformity assessment   
procedures used.  It is acceptable for a manufacturer to issue a DoC with   
another company's name on it - when that company is selling the product,   
for example where the product is badged with the seller's name, as long   
as the actual manufacturer's name appears on the DoC.

If a new manufacturer wants to take over complete responsibility for the   
certification of a product, then it is presumed that he has control over   
manufacturing and the actual manufacturer, if not a part of the company   
(such as being an approved subcontractor), may not change the design of   
the product without the approval of the new manufacturer.  In other words   
the new manufacturer becomes the design authority and controls the design   
of the product.  This is easy for self certification because the   
compliance documentation is simply passed across to the new manufacturer.   
 The new manufacturer then issues a new DoC.

However, if a third party has been used in the assessment procedure then   
this produces complications for the new manufacturer.  This is   
particularly the case where the QA system used by the original   
manufacturer has been assessed by a notified body.  The product approval   
and the approval of the QA system is completely dependent on the   
assessment by the notified body.  This is not transferable.  So if a   
notified body has been involved in any assessment via an assessment of   
the QA system, e.g. Annex V procedures of the R&TTED, then the new   
manufacturer will have to go through the same process again.

If the new manufacturer leaves compliance responsibility with the   
original manufacturer and is simply treated as an approved subcontractor   
then the notified body may be willing to accept the original   
certification and the original manufacturer issues the DoC with the new   
manufacturer named as a supplier of the product.

Confused?  It is all really quite logical and the only thing the EU   
really want to know is where to place the blame when something goes   
wrong.

Regards

Martin Green
Technology International (Europe) Ltd.
Tel.: (44) 1793 783137
Fax: (44) 1793 782310

 -Original Message-
From:   Wismer, Sam [SMTP:wisme...@lxe.com]
Sent:   12 September 2000 14:40
To: EMC Forum (E-mail); martin
Subject:RTTE Radio Verification

   


Group,
Interesting discussion on FCC Verification of OEM ITE equipment.

I have another twist that includes radio and the EU.

Company A has a 2.4GHz radio device that they have self declared to the   
RTTE
Directive in accordance with Annex V of the directive.

Company B, with no internationally recognized quality system in place and
has not been assessed by a Notified Body,  wishes to OEM the radio device
and to assume the existing approvals.  In effect appear to the world as   
the
manufacturer.  In the USA that can be done via a Grantee change with the
FCC.  With that, company B assumes the FCC approval that company A has
obtained and now enjoys it's own FCC identity.  This allows company B to
file permissive change applications with no involvement by Company A.   
 This
also used to be the case in the EU before the RTTE Directive.  However,   
is
it still possible between company A, that used Annex V to declare
compliance, and company B who wishes to assume that approval even if   
company
B does not have the quality system in place that is required by Annex V,
which the approval is declared to?



~
Sam Wismer
RF Approvals Engineer
LXE, Inc.
(770) 447-4224 Ext. 3654

Visit Our Website at:
http://www.lxe.com



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ASTME E 648

[Rafael González]

Dear Sirs,

We are looking for the UL equivalent flammability standards to: 
- ASTME E 648
- DIN 4102
- NF-P 90-501

Thanks in advance for your help,

Rafael González Licerán
Electrical safety technician



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