Packaging material

[Rick Loiselle]

Hello,

Has anyone heard of EPS (polystyrene?) packaging material soon to be "not
accepted" in the European Community because it is a Non-recycling material?

Best Regards,

Rick Loiselle
Boston Acoustics
Compliance Engineer
Peabody, MA (USA)

RE: Reflector for Radiated Immunity Testing

[Brodie Pedersen]

Brian 
I used to work at the TUVPS facility you mentioned and I belive they 
stilll have that reflector although they stopped using it a couple of 
years ago.  Basically it was constructed from a single sheet of the 
alluminum foil coated sheathing material popular in home 
construction today.  It was cut kiddy corner end to end and the 
pieces were put back together to form the wedge.  It was put back 
together with lots of 2" copper tape.  It was then placed on the floor 
directly below the antenna.  With the wedge in place they still had 
extra absorber on the floor in front of the EUT for table top 
equipment anyway.  This gave a pretty good field but it was tedious 
to set up for field uniformity playback use.  

Brodie Pedersen
SQA Engineer
NONIN Medical Inc.

-
This message is coming from the emc-pstc discussion list.
To cancel your subscription, send mail to majord...@ieee.org
with the single line: "unsubscribe emc-pstc" (without the
quotes).  For help, send mail to ed.pr...@cubic.com,
jim_bac...@monarch.com, ri...@sdd.hp.com, or
roger.volgst...@compaq.com (the list administrators).

RE: Reflector for Radiated Immunity Testing

[UMBDENSTOCK]

I found my copy of the original referenced article.  One place it showed up
was EMC Test and Design, Feb/March, 1995.  The article was titled "IEC
1000-4-3: The New Radiated Immunity Test" by Darren McCarthy of the HP
Company.  On page 31 the dimensions of the wedge and construction techniques
are given.  Total cost: $96 less rivets.

Don Umbdenstock
Sensormatic

> --
> From: Matejic, Mirko[SMTP:mmate...@foxboro.com]
> Reply To: Matejic, Mirko
> Sent: Wednesday, October 27, 1999 11:05 AM
> To:   emc-p...@majordomo.ieee.org
> Subject:  RE: Reflector for Radiated Immunity Testing
> 
> 
> Brian,
> 
> The other, bit lesser corporate exercise program you could 
> consider would be to roll-over GND plane over ferrite tiled 
> floor. GND plane could be chicken mesh grounded at etches.
> 
> Did you measure NSA with floor tiles in place?
> 
> Mirko
> 
> > -Original Message-
> > From:   Brian At Work [SMTP:bkundew...@qtm.net]
> > Sent:   Wednesday, October 27, 1999 5:24
> > To: Bailin Ma; emc-p...@majordomo.ieee.org
> > Subject:Re: Reflector for Radiated Immunity Testing
> > 
> > 
> > Barry,
> > 
> > The "reflector" takes the place of the absorbing material that goes on
> the
> > floor between the EUT and the antenna.   We have a 10 meter
> semi-anachoic
> > chamber in which we perform both emissions and immunity tests. To
> perform
> > the radiated immunity test we have to haul in 42 tile panels weighing
> > 30lbs
> > each and set them into place. After the test, we have to pick them all
> > back
> > up again. We look at it as our corporate exercise program. .
> 
> -
> This message is coming from the emc-pstc discussion list.
> To cancel your subscription, send mail to majord...@ieee.org
> with the single line: "unsubscribe emc-pstc" (without the
> quotes).  For help, send mail to ed.pr...@cubic.com,
> jim_bac...@monarch.com, ri...@sdd.hp.com, or
> roger.volgst...@compaq.com (the list administrators).
> 
> 

-
This message is coming from the emc-pstc discussion list.
To cancel your subscription, send mail to majord...@ieee.org
with the single line: "unsubscribe emc-pstc" (without the
quotes).  For help, send mail to ed.pr...@cubic.com,
jim_bac...@monarch.com, ri...@sdd.hp.com, or
roger.volgst...@compaq.com (the list administrators).

Permanence of marking test.

[Ehler, Kyle]

I'm sorry to plague the list with such a mundane query, but I am forced to
perform the UL1950 '1.7.15 Permanence of Marking' test using HEXANE as the
test solvent.  I cannot find a local source willing to sell less than
55Gal
0.5L would probably last me ten years.

Anybody know of a source?
Kyle Ehler  kyle.eh...@lsil.com   
Assistant Design Engineer
LSI Logic Corporation
3718 N. Rock Road
U.S.A.  Wichita, Kansas  67226
Ph. 316 636 8657
Fax 316 636 8889
Fax 316 636 8315

-
This message is coming from the emc-pstc discussion list.
To cancel your subscription, send mail to majord...@ieee.org
with the single line: "unsubscribe emc-pstc" (without the
quotes).  For help, send mail to ed.pr...@cubic.com,
jim_bac...@monarch.com, ri...@sdd.hp.com, or
roger.volgst...@compaq.com (the list administrators).

RE: Electronic unit panel sizes

[WOODS]

I believe that there is an EIA standard for these dimensions.

--
From:  Schanker, Jack [SMTP:jschan...@adaptivebroadband.com]
Sent:  Wednesday, October 27, 1999 2:53 PM
To:  emc-p...@ieee.org; Brian Harlowe
Subject:  RE: Electronic unit panel sizes


Brian:

My understanding is that the U comes from "rack Units", where the
incremental rack height is 1.75 inches and then continues in integer
multiples. So, 7.0" 8.75" etc are all allowable rack panel heights,
but 11.0
inches is not. It sounds to me like the American who chose 11 inches
for a
rack-mounted piece of gear made a bad choice.

If they made that bad choice, you also want to carefully check the
number
and spacing of the mounting holes on the front panel or rack ears to
see if
they align with standard rack rail hole spacings (I don't have that
information handy, and seem to recall more than one "standard"
(sic)).

This may not be any help except to confirm that you're correct, not
crazy.

Regards,

Jack

Jacob Z. Schanker, P.E.
Director of Agency Compliance
Adaptive Broadband Corporation
175 Science Parkway
Rochester, NY 14620 USA
+716 242 8454 (voice)
+716 241 5590 (fax)
jschan...@adaptivebroadband.com
 



--
From:  Brian Harlowe [SMTP:bharl...@vgscientific.com]
Sent:  Wednesday, October 27, 1999 12:30 PM
To:  emc-p...@ieee.org
Subject:  Electronic unit panel sizes


Excuse me from drifting away from the main topics of this
forum. But

can one of you whizzy american engineers help a poor
englishman out.

In the UK ( and Europe) front panels are measured in Us
where 1U 
equals 1.75 ins or 44.45 millimetres.

Does this system operate in the states? The reason I ask is
we have 
an American unit to accomodate that 11 inches high which
works out
at 
6.29U!!!

Help

Brian Harlowe  
* opinions expressed here are personal and in no way reflect
the
position of VG Scientific

-
This message is coming from the emc-pstc discussion list.
To cancel your subscription, send mail to majord...@ieee.org
with the single line: "unsubscribe emc-pstc" (without the
quotes).  For help, send mail to ed.pr...@cubic.com,
jim_bac...@monarch.com, ri...@sdd.hp.com, or
roger.volgst...@compaq.com (the list administrators).


-
This message is coming from the emc-pstc discussion list.
To cancel your subscription, send mail to majord...@ieee.org
with the single line: "unsubscribe emc-pstc" (without the
quotes).  For help, send mail to ed.pr...@cubic.com,
jim_bac...@monarch.com, ri...@sdd.hp.com, or
roger.volgst...@compaq.com (the list administrators).


-
This message is coming from the emc-pstc discussion list.
To cancel your subscription, send mail to majord...@ieee.org
with the single line: "unsubscribe emc-pstc" (without the
quotes).  For help, send mail to ed.pr...@cubic.com,
jim_bac...@monarch.com, ri...@sdd.hp.com, or
roger.volgst...@compaq.com (the list administrators).

RE: [SI-LIST] : Comments from your SI seminar (SendII)`

[Grasso, Charles (Chaz)]

Now hold on - in your answer you indicated a high frequency
signalling environment.

Remember - capacitance(& inductance) = delay = skew. Is this
what we are really looking for in a high frequency signalling
environment - Especially is skew is important?

OK if the timing diagram is NOT critical and the signal
is not "important" (eg reset) then maybe.

Don't you mean that the high frequency content of the 
edges may couple across?

-Original Message-
From: Denomme, Paul S. [mailto:paul.deno...@viasystems.com]
Sent: Wednesday, October 27, 1999 1:01 PM
To: 'si-l...@silab.eng.sun.com'
Cc: 'EMC Group'
Subject: RE: [SI-LIST] : Comments from your SI seminar (SendII)`


In regards to comment 1.  In a high frequency signalling environment, The
return current will flow on the nearest plane whether it is power or ground.
If you have two planes coupled closely togther you create a capacitor which
the high frequency return current uses to traverse the planes and takes the
path of least impedance.
If there were not two planes coupled together, it would be an EMI
catastrophe and you would not know where the return current is flowing.  

Regarding comment 2, he was stating that grounding in multiple locations is
a bad idea.  This can create some ground loops within the chassis. There
will be some type of potential difference from one chassis connection point
to another and this will create some current in the chassis.  This is very
bad from an EMI perspective.
He believes one Solid connection to the ground plane is sufficient. 

I would like to hear a take from an EMI person.

Regards,

Paul S. Denomme
Viasystems Inc.
Richmond, VA
paul.deno...@viasystems.com


> -Original Message-
> From: Grasso, Charles (Chaz) [SMTP:gra...@louisville.stortek.com]
> Sent: Wednesday, October 27, 1999 2:26 PM
> To:   'leeritc...@earthlink.net'
> Cc:   'EMC Group'; 'Signal Integrity'
> Subject:  [SI-LIST] : Comments from your SI seminar (SendII)`
> 
> Sir,
> 
> A collegue of mine has recently taken your SI seminar.
> In discussing the class with him I came across two
> statements from the semiar that I would like to discuss
> with you and others in the EMC profession.
> 
> Comment 1. On page 109 there is a slide that states:
> 
> Traces crossing cuts in planes can function properly.
> 
> Please explain your rationale.
> 
> Comment 2: On page 110 there is a slide title:
> 
> A bad grounding idea.
> 
> The picture is of a board with multiple ground connections
> and distances maked off as lambda/20
> 
> Clearly this is a shot at the multiple stitching concept that
> is prevalent in the EMC world.
> 
> One of the problems in the EMC/SI world is that there is 
> contradictory information provided to the poor consumer.
> 
> I look forward to a lively debate on these issues. 
> 
> 
>  To unsubscribe from si-list: send e-mail to
> majord...@silab.eng.sun.com. In the BODY of message put: UNSUBSCRIBE
> si-list, for more help, put HELP.  si-list archives are accessible at
> http://www.qsl.net/wb6tpu/si-list 

 To unsubscribe from si-list: send e-mail to
majord...@silab.eng.sun.com. In the BODY of message put: UNSUBSCRIBE
si-list, for more help, put HELP.  si-list archives are accessible at
http://www.qsl.net/wb6tpu/si-list 

-
This message is coming from the emc-pstc discussion list.
To cancel your subscription, send mail to majord...@ieee.org
with the single line: "unsubscribe emc-pstc" (without the
quotes).  For help, send mail to ed.pr...@cubic.com,
jim_bac...@monarch.com, ri...@sdd.hp.com, or
roger.volgst...@compaq.com (the list administrators).

RE: Electronic unit panel sizes

[SparacinoG]

Yes, I believe you've got it !

> -Original Message-
> From: Brian Harlowe [SMTP:bharl...@vgscientific.com]
> Sent: Wednesday, October 27, 1999 12:30 PM
> To:   emc-p...@ieee.org
> Subject:  Electronic unit panel sizes
> 
> 
> Excuse me from drifting away from the main topics of this forum. But 
> can one of you whizzy american engineers help a poor englishman out.
> 
> In the UK ( and Europe) front panels are measured in Us where 1U 
> equals 1.75 ins or 44.45 millimetres.
> 
> Does this system operate in the states? The reason I ask is we have 
> an American unit to accomodate that 11 inches high which works out at 
> 6.29U!!!
> 
> Help
> 
> Brian Harlowe  
> * opinions expressed here are personal and in no way reflect the position of 
> VG Scientific
> 
> -
> This message is coming from the emc-pstc discussion list.
> To cancel your subscription, send mail to majord...@ieee.org
> with the single line: "unsubscribe emc-pstc" (without the
> quotes).  For help, send mail to ed.pr...@cubic.com,
> jim_bac...@monarch.com, ri...@sdd.hp.com, or
> roger.volgst...@compaq.com (the list administrators).
> 

-
This message is coming from the emc-pstc discussion list.
To cancel your subscription, send mail to majord...@ieee.org
with the single line: "unsubscribe emc-pstc" (without the
quotes).  For help, send mail to ed.pr...@cubic.com,
jim_bac...@monarch.com, ri...@sdd.hp.com, or
roger.volgst...@compaq.com (the list administrators).

RE: [SI-LIST] : Comments from your SI seminar (SendII)`

[Denomme, Paul S.]

In regards to comment 1.  In a high frequency signalling environment, The
return current will flow on the nearest plane whether it is power or ground.
If you have two planes coupled closely togther you create a capacitor which
the high frequency return current uses to traverse the planes and takes the
path of least impedance.
If there were not two planes coupled together, it would be an EMI
catastrophe and you would not know where the return current is flowing.  

Regarding comment 2, he was stating that grounding in multiple locations is
a bad idea.  This can create some ground loops within the chassis. There
will be some type of potential difference from one chassis connection point
to another and this will create some current in the chassis.  This is very
bad from an EMI perspective.
He believes one Solid connection to the ground plane is sufficient. 

I would like to hear a take from an EMI person.

Regards,

Paul S. Denomme
Viasystems Inc.
Richmond, VA
paul.deno...@viasystems.com


> -Original Message-
> From: Grasso, Charles (Chaz) [SMTP:gra...@louisville.stortek.com]
> Sent: Wednesday, October 27, 1999 2:26 PM
> To:   'leeritc...@earthlink.net'
> Cc:   'EMC Group'; 'Signal Integrity'
> Subject:  [SI-LIST] : Comments from your SI seminar (SendII)`
> 
> Sir,
> 
> A collegue of mine has recently taken your SI seminar.
> In discussing the class with him I came across two
> statements from the semiar that I would like to discuss
> with you and others in the EMC profession.
> 
> Comment 1. On page 109 there is a slide that states:
> 
> Traces crossing cuts in planes can function properly.
> 
> Please explain your rationale.
> 
> Comment 2: On page 110 there is a slide title:
> 
> A bad grounding idea.
> 
> The picture is of a board with multiple ground connections
> and distances maked off as lambda/20
> 
> Clearly this is a shot at the multiple stitching concept that
> is prevalent in the EMC world.
> 
> One of the problems in the EMC/SI world is that there is 
> contradictory information provided to the poor consumer.
> 
> I look forward to a lively debate on these issues. 
> 
> 
>  To unsubscribe from si-list: send e-mail to
> majord...@silab.eng.sun.com. In the BODY of message put: UNSUBSCRIBE
> si-list, for more help, put HELP.  si-list archives are accessible at
> http://www.qsl.net/wb6tpu/si-list 

 To unsubscribe from si-list: send e-mail to majord...@silab.eng.sun.com. 
In the BODY of message put: UNSUBSCRIBE si-list, for more help, put HELP.  
si-list archives are accessible at http://www.qsl.net/wb6tpu/si-list 

RE: Electronic unit panel sizes

[Schanker, Jack]

Brian:

My understanding is that the U comes from "rack Units", where the
incremental rack height is 1.75 inches and then continues in integer
multiples. So, 7.0" 8.75" etc are all allowable rack panel heights, but 11.0
inches is not. It sounds to me like the American who chose 11 inches for a
rack-mounted piece of gear made a bad choice.

If they made that bad choice, you also want to carefully check the number
and spacing of the mounting holes on the front panel or rack ears to see if
they align with standard rack rail hole spacings (I don't have that
information handy, and seem to recall more than one "standard" (sic)).

This may not be any help except to confirm that you're correct, not crazy.

Regards,

Jack

Jacob Z. Schanker, P.E.
Director of Agency Compliance
Adaptive Broadband Corporation
175 Science Parkway
Rochester, NY 14620 USA
+716 242 8454 (voice)
+716 241 5590 (fax)
jschan...@adaptivebroadband.com  



--
From:  Brian Harlowe [SMTP:bharl...@vgscientific.com]
Sent:  Wednesday, October 27, 1999 12:30 PM
To:  emc-p...@ieee.org
Subject:  Electronic unit panel sizes


Excuse me from drifting away from the main topics of this forum. But

can one of you whizzy american engineers help a poor englishman out.

In the UK ( and Europe) front panels are measured in Us where 1U 
equals 1.75 ins or 44.45 millimetres.

Does this system operate in the states? The reason I ask is we have 
an American unit to accomodate that 11 inches high which works out
at 
6.29U!!!

Help

Brian Harlowe  
* opinions expressed here are personal and in no way reflect the
position of VG Scientific

-
This message is coming from the emc-pstc discussion list.
To cancel your subscription, send mail to majord...@ieee.org
with the single line: "unsubscribe emc-pstc" (without the
quotes).  For help, send mail to ed.pr...@cubic.com,
jim_bac...@monarch.com, ri...@sdd.hp.com, or
roger.volgst...@compaq.com (the list administrators).


-
This message is coming from the emc-pstc discussion list.
To cancel your subscription, send mail to majord...@ieee.org
with the single line: "unsubscribe emc-pstc" (without the
quotes).  For help, send mail to ed.pr...@cubic.com,
jim_bac...@monarch.com, ri...@sdd.hp.com, or
roger.volgst...@compaq.com (the list administrators).

RE: Electronic unit panel sizes

[Andrews, Kurt]

Brian,

Yes the U measurements are used in the United States. As you have found out
that does not mean that all units have a height that are in whole number
multiples of the U measurement. I don't believe that there is any
requirement that they be a whole number multiple of 1U, at least here in the
U.S. Is there such a requirement in the UK? In most cases that I have seen
front panels are a whole number multiple of 1U, but not always. We have
designed units that are whole number multiples of 1U, such as 1U, 3U, 4U,
etc. We have also designed equipment that is an odd size, such as 3.75" or
2.14U. Hope this helps to clear up the confusion ( in reality it will
probably add more).

Best regards,

Kurt Andrews
Compliance Engineer
Tracewell Systems, Inc.
567 Enterprise Dr.
Westerville, OH 43081
Ph. 614-846-6175
Fax 614-846-7791
Email: kandr...@tracewell.com 


-Original Message-
From:   Brian Harlowe [SMTP:bharl...@vgscientific.com]
Sent:   Wednesday, October 27, 1999 12:30 PM
To: emc-p...@ieee.org
Subject:Electronic unit panel sizes


Excuse me from drifting away from the main topics of this forum. But

can one of you whizzy american engineers help a poor englishman out.

In the UK ( and Europe) front panels are measured in Us where 1U 
equals 1.75 ins or 44.45 millimetres.

Does this system operate in the states? The reason I ask is we have 
an American unit to accomodate that 11 inches high which works out
at 
6.29U!!!

Help

Brian Harlowe  
* opinions expressed here are personal and in no way reflect the
position of VG Scientific

-
This message is coming from the emc-pstc discussion list.
To cancel your subscription, send mail to majord...@ieee.org
with the single line: "unsubscribe emc-pstc" (without the
quotes).  For help, send mail to ed.pr...@cubic.com,
jim_bac...@monarch.com, ri...@sdd.hp.com, or
roger.volgst...@compaq.com (the list administrators).


-
This message is coming from the emc-pstc discussion list.
To cancel your subscription, send mail to majord...@ieee.org
with the single line: "unsubscribe emc-pstc" (without the
quotes).  For help, send mail to ed.pr...@cubic.com,
jim_bac...@monarch.com, ri...@sdd.hp.com, or
roger.volgst...@compaq.com (the list administrators).

[SI-LIST] : Comments from your SI seminar (SendII)`

[Grasso, Charles (Chaz)]

Sir,

A collegue of mine has recently taken your SI seminar.
In discussing the class with him I came across two
statements from the semiar that I would like to discuss
with you and others in the EMC profession.

Comment 1. On page 109 there is a slide that states:

Traces crossing cuts in planes can function properly.

Please explain your rationale.

Comment 2: On page 110 there is a slide title:

A bad grounding idea.

The picture is of a board with multiple ground connections
and distances maked off as lambda/20

Clearly this is a shot at the multiple stitching concept that
is prevalent in the EMC world.

One of the problems in the EMC/SI world is that there is 
contradictory information provided to the poor consumer.

I look forward to a lively debate on these issues. 


 To unsubscribe from si-list: send e-mail to majord...@silab.eng.sun.com. 
In the BODY of message put: UNSUBSCRIBE si-list, for more help, put HELP.  
si-list archives are accessible at http://www.qsl.net/wb6tpu/si-list 

[SI-LIST] : Comments from your SI seminar

[Grasso, Charles (Chaz)]

Sir,

A collegue of mine has recently taken your SI class.
In discussing the class with him I came across two
statements from the class that I would like to discuss
with you and others in the EMC profession.

Comment 1. On page 109 there is a slide that states:

Traces crossing cuts in planes can function properly.

Please explain your rationale.

Comment 2: On page 110 there is a slide title:

A bad grounding idea.

The picture is of a board with multiple ground connections
and distances maked off as lambda/20

Clearly this is a shot at the multiple stitching concept that
is prevalent in the EMC world.

One of the problems in the EMC/SI world is that there is 
contradictory information provided to the poor consumer.

I look forward to a lively debate on these issues. 

 To unsubscribe from si-list: send e-mail to majord...@silab.eng.sun.com. 
In the BODY of message put: UNSUBSCRIBE si-list, for more help, put HELP.  
si-list archives are accessible at http://www.qsl.net/wb6tpu/si-list 

Spain - EMC - marine

[Westin, Amund]

Members,

I have heard some rumours that Spanish Maritime Authorities have not
enforced  the LVD nor EMC directives so far (... for equipment not
covered by the marine directive...). 

Can anybody confirm this ?

Best regards
Amund Westin
Det Norske Veritas
* amund.wes...@dnv.com


-
This message is coming from the emc-pstc discussion list.
To cancel your subscription, send mail to majord...@ieee.org
with the single line: "unsubscribe emc-pstc" (without the
quotes).  For help, send mail to ed.pr...@cubic.com,
jim_bac...@monarch.com, ri...@sdd.hp.com, or
roger.volgst...@compaq.com (the list administrators).

Re: Reflector for Radiated Immunity Testing

[Brian Jones]

Brian At Work wrote:
> 
> I am in search of information about a reflector (sometimes call a
> "Wedge") that is used in place of rf absorbing material between the
> EUT and the antenna in the Radiated Immunity Testing (e.g.
> EN61000-4-3). I have searched the PSTC database without luck. I was
> told that it was maybe an article in ITEM 1997 magazine but I can't
> find in on their web site.
> 
> I'm mainly looking for dimensions and construction information as well
> as any important tips. We would like to use it for testing desktop
> products in a 10 meter chamber.
> 
> Thanks in advance,
> Brian Kunde
> Compliance Testing Center
> LECO Corp.
> St. Joseph, Michigan
> 
> 

Brian

A paper entitled "IEC 1000-4-3 Radiated Immunity Testing on a $100 
Budget" was presented at the 1994 IEEE EMC Symposium in Chicago, but it 
was not included in the symposium record.  Copies of the slides were 
handed out at the presentation.

The wedge was placed on the floor with the axis of the centre adjusted 
from 15 to 23 degrees to the floor, depending on the required height of 
the uniform field.  

The author of the paper was Darren McCarthy of the Hewlett Packard 
Company, Cupertino, CA - (408) 447 4070.  Perhaps you could contact him 
for more details.

Best wishes

Brian Jones
EMC Consultant and Competent Body Signatory


-
This message is coming from the emc-pstc discussion list.
To cancel your subscription, send mail to majord...@ieee.org
with the single line: "unsubscribe emc-pstc" (without the
quotes).  For help, send mail to ed.pr...@cubic.com,
jim_bac...@monarch.com, ri...@sdd.hp.com, or
roger.volgst...@compaq.com (the list administrators).

Re: Conducted emission problems

[Patrick Lawler]

Have you verified that the noise is being _generated_ by the fan?
In some cases, I've found system wiring that was picking up noise from another
part of the system, and 'carrying' it to the AC inlet.
If this seems plausible in your case, try stalling the fan (momentarily!), or
replacing the fan with a resistive load of the same power level.

On Mon, 25 Oct 1999 23:50:10 PDT, "Ray Levasseur" 
wrote:
>I was hoping I could get some suggestions from the group on a conducted 
>emission problem I am presently working on. I am measuring to the EN 55022 
>Class A levels and have a non compliant system air blower. The blower is an 
>Ametek Windjammer and is used to positively pressurize our product. The 
>blower is normally used in vacuum cleaners and is probably rarely used in IT 
>equipment. The blower is inexpensive and the supplier is not too keen to 
>provide the modifications to meet our requirements. We use the blower in 
>some of our products either off the line (230 Vac) or through the power  
>distribution system and the system ac line filter. I have tried the off the 
>shelf line filters (Corcom, Schaffner, Okaya, Delta and Spectrum Control) 
>but they all fizzle out below 200 kHz. The blower generates tons of noise 
>and I am having difficulty passing the levels at 150 kHz. I have tried 
>various caps across the line and line to ground but can't get the low end 
>solved. I was wondering if anyone has any experience with this type of 
>problem or has worked with the Ametek blower? Any suggestions would be 
>greatly appreciated.
>
>Ray Levasseur
>EMC Compliance
>Creo Products

--
Patrick Lawler
plaw...@west.net

-
This message is coming from the emc-pstc discussion list.
To cancel your subscription, send mail to majord...@ieee.org
with the single line: "unsubscribe emc-pstc" (without the
quotes).  For help, send mail to ed.pr...@cubic.com,
jim_bac...@monarch.com, ri...@sdd.hp.com, or
roger.volgst...@compaq.com (the list administrators).

Re: Reflector for Radiated Immunity Testing

[bma]

Brian and Mirko,

Thanks for your further explanations. Here is my understanding. Please review 
and correct.

(1) A semi-anechoic chamber has five absorbing planes and one reflected plane 
-- that is floor. There are two Electromagnetic waves from the antenna to the 
EUT: Direct and Reflected (via floor). In emission testing, we need the 
reflected waves for comparability with OATS. In immunity tests, however, we 
don't want the reflected wave. To eliminate the reflected wave at the EUT we 
may pave absorbing tile panels or pyramids on the middle part of floor. An 
alternative is to change the mirror reflection of the floor to random 
reflection. Most of those random reflected waves would go to five other 
absorbing planes. If my understanding did not go wrong, dimensions of shadow 
reflected wedges might not be very critical. You probably can try and error 
them. 

(2) A shielded room has six reflected planes. It is quite interesting to use 
it for immunity testing. Can Mirko or somebody else detail it? 
It seems to be difficult to perform immunity test over the whole frequency 
range of 30 to 1000 MHz even though paving some absorbing materials on part 
of walls and floor. We may use it for immunity debugging at couple of 
particular frequencies.


Best Regards,
Barry Ma
-- Original Text --

From: "Brian At Work" , on 10/27/99 5:25 AM:

Barry,

The "reflector" takes the place of the absorbing material that goes on the
floor between the EUT and the antenna.   We have a 10 meter semi-anachoic
chamber in which we perform both emissions and immunity tests. To perform
the radiated immunity test we have to haul in 42 tile panels weighing 30lbs
each and set them into place. After the test, we have to pick them all back
up again. We look at it as our corporate exercise program. But it can be
very time consuming, so we are looking for a quicker solution.

Many labs I have been to with a similar setup as mine uses a "reflector" in
place of the heavy tile panels.  We would like to do the same but I have not
been able to find information on the physical size, angle, etc..

Sorry I didn't explain this in more detail in my original email. Thanks to
all who have replied.

Brian Kunde
Compliance Testing Center
LECO Corp.

- Original Message -
From: Bailin Ma 
To: 
Sent: Tuesday, October 26, 1999 7:21 PM
Subject: RE: Reflector for Radiated Immunity Testing



Matejic and Brian,

Why not try ferrite tile paved on part of floor and wall in the Shielded
Room
to absorb some reflected waves?

B Ma
-- Original Text --

From: "Matejic, Mirko" , on 10/26/99 1:52 PM:


Brian,

Procedure was presented at IEEE EMC Symposium in Chicago in early
nineties, author was Darren McCarthy, HP, Cupertino, CA, (408) 447-4070,
title of his interesting and well attended presentation was something
like How to use Shielded Room for Radiated Immunity for $100.

Mirko Matejic

-
This message is coming from the emc-pstc discussion list.
To cancel your subscription, send mail to majord...@ieee.org
with the single line: "unsubscribe emc-pstc" (without the
quotes).  For help, send mail to ed.pr...@cubic.com,
jim_bac...@monarch.com, ri...@sdd.hp.com, or
roger.volgst...@compaq.com (the list administrators).




-
This message is coming from the emc-pstc discussion list.
To cancel your subscription, send mail to majord...@ieee.org
with the single line: "unsubscribe emc-pstc" (without the
quotes).  For help, send mail to ed.pr...@cubic.com,
jim_bac...@monarch.com, ri...@sdd.hp.com, or
roger.volgst...@compaq.com (the list administrators).






-
This message is coming from the emc-pstc discussion list.
To cancel your subscription, send mail to majord...@ieee.org
with the single line: "unsubscribe emc-pstc" (without the
quotes).  For help, send mail to ed.pr...@cubic.com,
jim_bac...@monarch.com, ri...@sdd.hp.com, or
roger.volgst...@compaq.com (the list administrators).

RE: Electronic unit panel sizes

[rbusche]

Brian
We manufacturer system where the components are routinely rack mounted. All
of our filler plates and assemblies as defined in "U"s, so yes it does (or
should) work here in the U.S.

Rick Busche
Evans & Sutherland
rbus...@es.com

-Original Message-
From:   Brian Harlowe [mailto:bharl...@vgscientific.com]
Sent:   Wednesday, October 27, 1999 10:30 AM
To: emc-p...@ieee.org
Subject:Electronic unit panel sizes


Excuse me from drifting away from the main topics of this
forum. But 
can one of you whizzy american engineers help a poor
englishman out.

In the UK ( and Europe) front panels are measured in Us
where 1U 
equals 1.75 ins or 44.45 millimetres.

Does this system operate in the states? The reason I ask is
we have 
an American unit to accomodate that 11 inches high which
works out at 
6.29U!!!

Help

Brian Harlowe  
* opinions expressed here are personal and in no way reflect
the position of VG Scientific

-
This message is coming from the emc-pstc discussion list.
To cancel your subscription, send mail to majord...@ieee.org
with the single line: "unsubscribe emc-pstc" (without the
quotes).  For help, send mail to ed.pr...@cubic.com,
jim_bac...@monarch.com, ri...@sdd.hp.com, or
roger.volgst...@compaq.com (the list administrators).


-
This message is coming from the emc-pstc discussion list.
To cancel your subscription, send mail to majord...@ieee.org
with the single line: "unsubscribe emc-pstc" (without the
quotes).  For help, send mail to ed.pr...@cubic.com,
jim_bac...@monarch.com, ri...@sdd.hp.com, or
roger.volgst...@compaq.com (the list administrators).

Re: IEC 364 - Definition of SELV

[Rich Nute]

Hi Kevin:


>   Is IEC 536 the base document for the definition of SELV?  

>   (where it says that "SELV" means "Safety Extra-Low Voltage")?  

Yes.

IEC 536, Definitions, Sub-clause 2.6:

"Safety extra-low voltage (SELV)"


HISTORY LESSON
==

Prior to IEC 536, I believe SELV was not defined as such, but
the concept of SELV, i.e., low voltage protected from higher 
voltages did indeed exist.

CEE Publication 10, Electric Motor-Operated Appliances, October,
1964, has the following definition:

"Extra-low voltage denotes a nominal voltage not exceeding
42 V between conductors and between conductors and earth, 
the no-load voltage not exceeding 50 V.

"When extra-low voltage is obtained from the supply mains,
it must be through a safety isolating transformer or a 
converter with separate windings."

Due to its similarity with the definition from IEC 536, it 
appears this CEE 10 ELV definition evolved to SELV.

CEE:   International Commission on Rules for the Approval of
   Electrical Equipment.

(I believe the CEE was absorbed by CEN and CENELEC.)

CEE Members:  Austria, Belgium, Czechoslovakia, Denmark, 
   Germany (FR), Finalnd, France, Greece, Hungary, Italy,
   Netherlands, Norway, Poland, Spain, Sweden, Switzerland,
   United Kingdom, Yugoslavia.


Best regards,
Rich




>   From owner-emc-p...@majordomo.ieee.org Tue Oct 26 23:44:11 PDT 1999
>   Received: from hpsdlo.sdd.hp.com (hpsdlo-sw.sdd.hp.com [15.80.36.40]) by 
> hpsdlfsg.sdd.hp.com with ESMTP (8.7.6/8.7.3 TIS 5.0/sdd epg) id XAA23435 for 
> ; Tue, 26 Oct 1999 23:44:11 -0700 (PDT)
>   Received: from ruebert.ieee.org (ruebert.ieee.org [199.172.136.3])
>   by hpsdlo.sdd.hp.com (8.8.6 (PHNE_14041)/8.8.5btis+epg) with ESMTP id 
> XAA04752
>   for ; Tue, 26 Oct 1999 23:44:09 -0700 (PDT)
>   Received:  by ruebert.ieee.org (8.8.8+Sun/8.8.8)
>   id CAA20446; Wed, 27 Oct 1999 02:19:26 -0400 (EDT)
>   Date: Wed, 27 Oct 1999 02:18:15 -0400
>   From: Kevin Richardson 
>   Subject: Re: IEC 364 - Definition of SELV
>   To: Rich Nute 
>   Cc: "[unknown]" 
>   Message-ID: <199910270218_mc2-8a97-1...@compuserve.com>
>   MIME-Version: 1.0
>   Content-Type: text/plain;
>charset=ISO-8859-1
>   Content-Disposition: inline
>   Content-Transfer-Encoding: 8bit
>   X-MIME-Autoconverted: from quoted-printable to 8bit by ruebert.ieee.org id 
> CAA20443
>   Sender: owner-emc-p...@majordomo.ieee.org
>   Precedence: bulk
>   Reply-To: Kevin Richardson 
>   X-Resent-To: Multiple Recipients 
>   X-Listname: emc-pstc
>   X-Info: Help requests to  emc-pstc-requ...@majordomo.ieee.org
>   X-Info: [Un]Subscribe requests to  majord...@majordomo.ieee.org
>   X-Moderator-Address: emc-pstc-appro...@majordomo.ieee.org
>   
>   
>   Hi Rich,
>   
>   Thank you for devoting so much time to reply.  This is just what I needed. 
>   I am familiar with IEC 60950 and I wanted to be able to compare the
>   definitions.  Thank you.
>   
>   One other question to Rich or anyone else that can help.
>   
>   Is IEC 536 the base document for the definition of SELV?  In addition to
>   how SELV is expressed in IEC 364 I am also trying to confirm the base
>   standard in the IEC responsible for the SELV definition.  Is it IEC 536 or
>   some other document?  In which standard or guide is the term SELV spelt out
>   (where it says that "SELV" means "Safety Extra-Low Voltage")?  There must
>   be a base IEC document somewhere that defines the term.
>   
>   Best regards,
>   Kevin
>
>   > 
>   > Hi Kevin:
>   > 
>   > 
>   > >   Can anyone please provide the SELV definition from IEC 364?
>   > 
>   > I'm working from some old documents, but...
>   > 
>   > SELV is not expressly defined in IEC 364-4-41.  Instead,
>   > it specifies "Protection by safety extra-low voltage."
>   > 
>   > It says:
>   > 
>   > "Protection against electric shock in normal service
>   > and in case of a fault is deemed to be ensured when:
>   > 
>   > - the nominal voltage cannot exceed the upper limit
>   >   of Voltage Band I*,
>   > 
>   > - the supply is from one of the safety sources listed
>   >   in Sub-clause 411.1.2, and
>   > 
>   > - the conditions of Sub-clause 411.1.3 are fulfilled."
>   > 
>   > "*See IEC Publication 449: Voltage Bands for Electrical
>   >   Installations of Buildings."
>   > 
>   > The safety sources are:
>   > 
>   > - a safety isolating transformer,
>   > 
>   > - a source of current providing a degree of safety 
>   >   equivalent to that of the safety isolating transformer
>   >   (e.g., motor generators with windings providing 
>   >   equivalent isolation),
>   > 
>   > - an electrochemical source (e.g., a battery) or another
>   >   source independent of a higher-voltage circuit (e.g., a
>   >   diesel-driven generator,
>   > 
>   > - certain electronic devices complying with appropriate
>   >   standards where measure have been tak

RE: Immunity Requirements for Australia

[Edward Fitzgerald]

Dear Martin,

At the present time the ACA has not included any immunity requirements
under their EMC Framework, although new EMR (ElectroMagnetic Radiation)
requirements have been introduced since February these are not yet
applicable to ISM.

The following site has some further information should you wish to
confirm the above: http://www.ets-tele.com/tics/global/au/index.htm

Best regards,
Edward Fitzgerald
Director
GSM Tel. : +44 4685 33 100

European Technology Services (Australia) Pty. Ltd.
Specialist Global Compliance and Regulatory Consultancy
Regional Offices in Australia, Canada and the UK.



-Original Message-
From: mart...@panametrics.com [mailto:mart...@panametrics.com]
Sent: 14 September 1999 22:18
To: emc-p...@ieee.org
Subject: Immunity Requirements for Australia



 Hi everyone, 
 
 Dose anyone know what the Immunity requirements for Australia are?
We 
 are using EN 61326, for ISM equipment, for Europe. We know about
the 
 requirements for Emissions, AS /NZS 2064:1997 and that they are the

 same as EN 55011. 
 
 Thank you in advance
 Charlie Martin

-
This message is coming from the emc-pstc discussion list.
To cancel your subscription, send mail to majord...@ieee.org
with the single line: "unsubscribe emc-pstc" (without the
quotes).  For help, send mail to ed.pr...@cubic.com,
jim_bac...@monarch.com, ri...@sdd.hp.com, or
roger.volgst...@compaq.com (the list administrators).


-
This message is coming from the emc-pstc discussion list.
To cancel your subscription, send mail to majord...@ieee.org
with the single line: "unsubscribe emc-pstc" (without the
quotes).  For help, send mail to ed.pr...@cubic.com,
jim_bac...@monarch.com, ri...@sdd.hp.com, or
roger.volgst...@compaq.com (the list administrators).

Electronic unit panel sizes

[Brian Harlowe]

Excuse me from drifting away from the main topics of this forum. But 
can one of you whizzy american engineers help a poor englishman out.

In the UK ( and Europe) front panels are measured in Us where 1U 
equals 1.75 ins or 44.45 millimetres.

Does this system operate in the states? The reason I ask is we have 
an American unit to accomodate that 11 inches high which works out at 
6.29U!!!

Help

Brian Harlowe  
* opinions expressed here are personal and in no way reflect the position of VG 
Scientific

-
This message is coming from the emc-pstc discussion list.
To cancel your subscription, send mail to majord...@ieee.org
with the single line: "unsubscribe emc-pstc" (without the
quotes).  For help, send mail to ed.pr...@cubic.com,
jim_bac...@monarch.com, ri...@sdd.hp.com, or
roger.volgst...@compaq.com (the list administrators).

RE: Reflector for Radiated Immunity Testing

[Matejic, Mirko]

Brian,

The other, bit lesser corporate exercise program you could 
consider would be to roll-over GND plane over ferrite tiled 
floor. GND plane could be chicken mesh grounded at etches.

Did you measure NSA with floor tiles in place?

Mirko

> -Original Message-
> From: Brian At Work [SMTP:bkundew...@qtm.net]
> Sent: Wednesday, October 27, 1999 5:24
> To:   Bailin Ma; emc-p...@majordomo.ieee.org
> Subject:  Re: Reflector for Radiated Immunity Testing
> 
> 
> Barry,
> 
> The "reflector" takes the place of the absorbing material that goes on the
> floor between the EUT and the antenna.   We have a 10 meter semi-anachoic
> chamber in which we perform both emissions and immunity tests. To perform
> the radiated immunity test we have to haul in 42 tile panels weighing
> 30lbs
> each and set them into place. After the test, we have to pick them all
> back
> up again. We look at it as our corporate exercise program. .

-
This message is coming from the emc-pstc discussion list.
To cancel your subscription, send mail to majord...@ieee.org
with the single line: "unsubscribe emc-pstc" (without the
quotes).  For help, send mail to ed.pr...@cubic.com,
jim_bac...@monarch.com, ri...@sdd.hp.com, or
roger.volgst...@compaq.com (the list administrators).

RE: Keeping up with technology

[Gary McInturff]

I believe Tania is correct for the following reasons.
If its says Listed and still has a manufacturers name or model number - fix
it in the report. Listed devices don't need that information in the report.
Only that it is Listed and the ratings. Listed products by their designation
are supposed to be able to be used without error by the end user. Typically,
they plug it in and go. Listed products are also required to carry the
Listed logo providing the FUS inspectors with instant confirmation of the
product - as long as it meets whatever ratings were originally provided.
Recognized component on the other hand, may have conditions of acceptability
along with them that may make them unsuitable in applications where similar
devices are used - but which don't have the conditions of acceptability.
They also are not required to carry a Recognition mark. This I believe is
most likely due to the small size of most recognized components.
Fortunately, many components do carry the marking but they are not required
to do so. 
There are better and less complex issues to demonstrate the point but a
particular hot pot of mine is power supplies. Unless you check carefully
sometimes these supplies are recognized as long as there is X amount of
airflow over the power supply. EG. It was running to hot during the test and
the manufacturer asked UL or whomever, to place a fan with some amount of
CFM across the supply during recognition testing.
As a condition of acceptance of the power supply in the end product there
then has to be at least the same amount of CFM over the supply. That doesn't
necessarily mean that if the end product has fan cooling that that air is
diverted over the supply in question. So before acceptance at least that
construction feature would have to be evaluated by the certifying agency.
On the other hand if this was a Listed wall  mount supply with a 10 volt 1
amp output. It stands on its own and the report should only describe it that
way. If you have a second vendor with identical ratings there is no
additional consideration for the power supply - or shouldn't be. If you are
having trouble with  your certifier over this -  educate them.
The text or equivalent isn't really required but it doesn't hurt either.
Take advantage of all text that works to your benefit. Minimum and Maximum
(well except with wire gauge) also by you flexibility.
Gary
-Original Message-
From:   Tac Pham [mailto:tp...@hcpower.com]
Sent:   Tuesday, October 26, 1999 10:45 AM
To: 'Derek Walton'
Cc: 'emc-pstc'
Subject:Re: Keeping up with technology



- Original Message -
From: Grant, Tania (Tania) 


Tania wrote:

> However, if the UL Report states:".Modem,
Listed...(or
> Recognized)..." this means that any modem, as long as
it is UL
> Listed/Recognized  and so marked, can be used in place of
the first modem
> that you submitted to UL.

Technically, we could replace the listed/recognized
components that so
marked. But, practically, UL required us to submit the
revised safety report
indicate that the new model number is added as alternate
component for FUS
purpose, unless it is specified in the "section general" of
UL report.

CSA allows manufacturer to put into the safety report "or
certified
equivalent" and we can directly replace as you mentioned.

Tac Pham
HC Power, inc.


-
This message is coming from the emc-pstc discussion list.
To cancel your subscription, send mail to majord...@ieee.org
with the single line: "unsubscribe emc-pstc" (without the
quotes).  For help, send mail to ed.pr...@cubic.com,
jim_bac...@monarch.com, ri...@sdd.hp.com, or
roger.volgst...@compaq.com (the list administrators).


-
This message is coming from the emc-pstc discussion list.
To cancel your subscription, send mail to majord...@ieee.org
with the single line: "unsubscribe emc-pstc" (without the
quotes).  For help, send mail to ed.pr...@cubic.com,
jim_bac...@monarch.com, ri...@sdd.hp.com, or
roger.volgst...@compaq.com (the list administrators).

RE: Reflector for Radiated Immunity Testing

[Matejic, Mirko]

In order to provide acceptable field uniformity for immunity 
testing to radiated field, you need to eliminate, attenuate 
or control reflections/standing waves. Ferrite tiles only on 
parts of the shielded room floor, walls and ceiling could do 
it, the question is to identify minimum tiled area.

Conclusions based on test results would be interesting 
topic to report at any future EMC Symposia.

Mirko Matejic

-
This message is coming from the emc-pstc discussion list.
To cancel your subscription, send mail to majord...@ieee.org
with the single line: "unsubscribe emc-pstc" (without the
quotes).  For help, send mail to ed.pr...@cubic.com,
jim_bac...@monarch.com, ri...@sdd.hp.com, or
roger.volgst...@compaq.com (the list administrators).

RE: EMC Test Lab near Dublin.

[Scott Douglas]

More importantly, where is lunch served?

Scott
s_doug...@ecrm.com
ECRM Incorporated
Tewksbury, MA  USA


-Original Message-
From: ghery.pet...@intel.com [mailto:ghery.pet...@intel.com]
Sent: Tuesday, October 26, 1999 7:03 PM
To: ken.ja...@emccompliance.com; nbels...@cisco.com;
l...@tempest-inc.com; emc-p...@majordomo.ieee.org
Subject: RE: EMC Test Lab near Dublin.
Importance: Low



The question is - does he have full capability to do testing for the EMC
directive due to his location, or his equipment?  Inquiring minds want to
know.
 

-Original Message-
From: Ken Javor [mailto:ken.ja...@emccompliance.com]
Sent: Tuesday, October 26, 1999 4:17 PM
To: Nathan Belsher; Lou Gnecco; emc-p...@majordomo.ieee.org
Subject: Re: EMC Test Lab near Dublin.


Note Mr. Belsher's priorities...

--
From: Nathan Belsher 
To: Lou Gnecco , emc-p...@majordomo.ieee.org
Subject: Re: EMC Test Lab near Dublin.
List-Post: emc-pstc@listserv.ieee.org
Date: Tue, Oct 26, 1999, 9:32 AM




Allen,

Yes,  Try Michael O'Dwyer.  His lab is in the backyard of the Guiness
brewery.  
He has full capability to do the EMC directive.

Nathan Belsher
Senior Compliance Engineer
Cisco Systems
DSL Hardware Development
Austin, Texas
(512)-378-1522

At 09:05 AM 10/26/99 -0400, Lou Gnecco wrote:
>>
>>Chris, call Michael O'Dwyer, the Managing Director at R.F. Technologies
Ltd. 
>> 40 Marrowbone Lane, Dublin 8, Ireland
>>from here, the number is
>>
>>011-353-1-454-5323
>>
>>email: r...@indigo.ie
>>
>>tell him I sent you.
>>
>>Lou
>>
>>LOUIS T. GNECCO M.S.E.E., PRESIDENT
>>TEMPEST INC. 112 ELDEN ST. HERNDON, VIRGINIA 20170
>>(703) "TEMPEST" (836-7378) FAX: 703 709 9565
>> >
>>
>>
>>-
>>This message is coming from the emc-pstc discussion list.
>>To cancel your subscription, send mail to majord...@ieee.org
>>with the single line: "unsubscribe emc-pstc" (without the
>>quotes).  For help, send mail to ed.pr...@cubic.com,
>>jim_bac...@monarch.com, ri...@sdd.hp.com, or
>>roger.volgst...@compaq.com (the list administrators).
>>
>>

Nathan Belsher
Senior EMC Engineer
DSL Hardware Development
Cisco Systems
Austin, Texas
(800)-550-2375 Ext. 81522
(512)-378-1522
(512)-378-1365 Fax
nbels...@cisco.com 



-
This message is coming from the emc-pstc discussion list.
To cancel your subscription, send mail to majord...@ieee.org
with the single line: "unsubscribe emc-pstc" (without the
quotes).  For help, send mail to ed.pr...@cubic.com,
jim_bac...@monarch.com, ri...@sdd.hp.com, or
roger.volgst...@compaq.com (the list administrators).




-
This message is coming from the emc-pstc discussion list.
To cancel your subscription, send mail to majord...@ieee.org
with the single line: "unsubscribe emc-pstc" (without the
quotes).  For help, send mail to ed.pr...@cubic.com,
jim_bac...@monarch.com, ri...@sdd.hp.com, or
roger.volgst...@compaq.com (the list administrators).

Re: Reflector for Radiated Immunity Testing

[Brian At Work]

Barry,

The "reflector" takes the place of the absorbing material that goes on the
floor between the EUT and the antenna.   We have a 10 meter semi-anachoic
chamber in which we perform both emissions and immunity tests. To perform
the radiated immunity test we have to haul in 42 tile panels weighing 30lbs
each and set them into place. After the test, we have to pick them all back
up again. We look at it as our corporate exercise program. But it can be
very time consuming, so we are looking for a quicker solution.

Many labs I have been to with a similar setup as mine uses a "reflector" in
place of the heavy tile panels.  We would like to do the same but I have not
been able to find information on the physical size, angle, etc..

Sorry I didn't explain this in more detail in my original email. Thanks to
all who have replied.

Brian Kunde
Compliance Testing Center
LECO Corp.

- Original Message -
From: Bailin Ma 
To: 
Sent: Tuesday, October 26, 1999 7:21 PM
Subject: RE: Reflector for Radiated Immunity Testing



Matejic and Brian,

Why not try ferrite tile paved on part of floor and wall in the Shielded
Room
to absorb some reflected waves?

B Ma
-- Original Text --

From: "Matejic, Mirko" , on 10/26/99 1:52 PM:


Brian,

Procedure was presented at IEEE EMC Symposium in Chicago in early
nineties, author was Darren McCarthy, HP, Cupertino, CA, (408) 447-4070,
title of his interesting and well attended presentation was something
like How to use Shielded Room for Radiated Immunity for $100.

Mirko Matejic

-
This message is coming from the emc-pstc discussion list.
To cancel your subscription, send mail to majord...@ieee.org
with the single line: "unsubscribe emc-pstc" (without the
quotes).  For help, send mail to ed.pr...@cubic.com,
jim_bac...@monarch.com, ri...@sdd.hp.com, or
roger.volgst...@compaq.com (the list administrators).




-
This message is coming from the emc-pstc discussion list.
To cancel your subscription, send mail to majord...@ieee.org
with the single line: "unsubscribe emc-pstc" (without the
quotes).  For help, send mail to ed.pr...@cubic.com,
jim_bac...@monarch.com, ri...@sdd.hp.com, or
roger.volgst...@compaq.com (the list administrators).





-
This message is coming from the emc-pstc discussion list.
To cancel your subscription, send mail to majord...@ieee.org
with the single line: "unsubscribe emc-pstc" (without the
quotes).  For help, send mail to ed.pr...@cubic.com,
jim_bac...@monarch.com, ri...@sdd.hp.com, or
roger.volgst...@compaq.com (the list administrators).

RE: Singapore

[Leslie Bai]

Amund:

The best person to answer your question
is Mr. W.H.Chong (Director of IT & Telecom Centre)
and Mrs.S.G.Chay (Director of E.E.Test Centre).

They are my ex-bosses a few years ago when I
was working with PSB.

Mr. Chong can be reached at (65)-7729721
email: cwh...@psb.gov.sg

Mrs.Chay can be reached at (65)-7729678
email: cha...@psb.gov.sg

Good luck,
Regards,
Leslie

 
> -Original Message-
> From: Westin, Amund [mailto:amund.wes...@dnv.com]
> Sent: Tuesday, October 26, 1999 7:12 AM
> To: 'emc-pstc'
> Subject: Singapore
> 
> 
> 
> What are the EMC and LVD requirements in Singapore ?
> Any suggestions ?
> 
> Thanks !
> 
> Amund Westin
> Det Norske Veritas
> * amund.wes...@dnv.com
> 
> 


=

__
Do You Yahoo!?
Bid and sell for free at http://auctions.yahoo.com

-
This message is coming from the emc-pstc discussion list.
To cancel your subscription, send mail to majord...@ieee.org
with the single line: "unsubscribe emc-pstc" (without the
quotes).  For help, send mail to ed.pr...@cubic.com,
jim_bac...@monarch.com, ri...@sdd.hp.com, or
roger.volgst...@compaq.com (the list administrators).

Re: IEC 364 - Definition of SELV

[Kevin Richardson]

Hi Rich,

Thank you for devoting so much time to reply.  This is just what I needed. 
I am familiar with IEC 60950 and I wanted to be able to compare the
definitions.  Thank you.

One other question to Rich or anyone else that can help.

Is IEC 536 the base document for the definition of SELV?  In addition to
how SELV is expressed in IEC 364 I am also trying to confirm the base
standard in the IEC responsible for the SELV definition.  Is it IEC 536 or
some other document?  In which standard or guide is the term SELV spelt out
(where it says that "SELV" means "Safety Extra-Low Voltage")?  There must
be a base IEC document somewhere that defines the term.

Best regards,
Kevin
 
> 
> Hi Kevin:
> 
> 
> >   Can anyone please provide the SELV definition from IEC 364?
> 
> I'm working from some old documents, but...
> 
> SELV is not expressly defined in IEC 364-4-41.  Instead,
> it specifies "Protection by safety extra-low voltage."
> 
> It says:
> 
> "Protection against electric shock in normal service
> and in case of a fault is deemed to be ensured when:
> 
> - the nominal voltage cannot exceed the upper limit
>   of Voltage Band I*,
> 
> - the supply is from one of the safety sources listed
>   in Sub-clause 411.1.2, and
> 
> - the conditions of Sub-clause 411.1.3 are fulfilled."
> 
> "*See IEC Publication 449: Voltage Bands for Electrical
>   Installations of Buildings."
> 
> The safety sources are:
> 
> - a safety isolating transformer,
> 
> - a source of current providing a degree of safety 
>   equivalent to that of the safety isolating transformer
>   (e.g., motor generators with windings providing 
>   equivalent isolation),
> 
> - an electrochemical source (e.g., a battery) or another
>   source independent of a higher-voltage circuit (e.g., a
>   diesel-driven generator,
> 
> - certain electronic devices complying with appropriate
>   standards where measure have been taken to ensure that, 
>   even in the case of aninternal fault, the voltage at the
>   outgoing termainals cannot exceed the values specified in
>   Sub-clause 411.1.1.
> 
> The definition of SELV appears in IEC 536:
> 
> "A voltage which does not exceed 50 V ac rms between
> conductors, or between any conductor and earth, in a 
> circuit which is isolated from the supply mains by means
> such as a safety isolating transformer or converter with
> separate windings."
> 
> IEC 950 defines SELV CIRCUIT:
> 
> "A secondary circuit which is so designed and protected 
> that under normal and single fault conditions, its 
> voltages do not exceed a safe value."
> 
> 
> SELV is a special case of ELV, Extra Low Voltage.  ELV is
> defined (or implied) as a maximum voltage value deemed not to 
> cause an electric shock.  SELV applies to an ELV where, in
> the absence of specific protective mechanisms, the ELV would
> exceed ELV under fault conditions.  So, SELV implies ELV with
> some means to prevent the voltage from exceeding ELV limits
> in the event of a fault.
> 
> A single-insulated transformer ELV secondary is ELV.
> 
> A double-insulated transformer ELV secondary is SELV.
> 
> An ELV battery is ELV.  It may or may not be SELV, depending
> on your point of view.  
> 
> 1:  Since the battery itself cannot exceed ELV under single-
> fault conditions, then it cannot be SELV.  Or, 
> 
> 2:  Since the battery itself cannot exceed ELV cannot exceed 
> ELV under single-fault conditions, then it must be SELV.  
> 
> However, as defined, SELV implies an included protective
> mechanism to limit the voltage in the event of a fault.  SELV
> also implies that the ELV is derived from a higher, non-ELV
> source.
> 
> If you accept that a battery is ELV, then the safety standards 
> require that the battery voltages cannot be touched!
> 
> 
> Best regards,
> Rich
> 
> 
> 
> 
> -
> This message is coming from the emc-pstc discussion list.
> To cancel your subscription, send mail to majord...@ieee.org
> with the single line: "unsubscribe emc-pstc" (without the
> quotes).  For help, send mail to ed.pr...@cubic.com,
> jim_bac...@monarch.com, ri...@sdd.hp.com, or
> roger.volgst...@compaq.com (the list administrators).
> 
> 
> 
> 
> 
> 
> --- Internet Header 
> Sender: owner-emc-p...@majordomo.ieee.org
> Received: from ruebert.ieee.org (ruebert.ieee.org [199.172.136.3])
>   by spdmgaaf.compuserve.com (8.9.3/8.9.3/SUN-1.7) with ESMTP id
UAA01279;
>   Tue, 26 Oct 1999 20:08:23 -0400 (EDT)
> Received:  by ruebert.ieee.org (8.8.8+Sun/8.8.8)
>   id UAA19661; Tue, 26 Oct 1999 20:07:41 -0400 (EDT)
> Date: Tue, 26 Oct 1999 17:06:45 -0700 (PDT)
> From: Rich Nute 
> Message-Id: <199910270006.raa26...@epgc478.sdd.hp.com>
> To: k...@compuserve.com
> Subject: Re: IEC 364 - Definition of SELV
> Cc: emc-p...@ieee.org
> In-Reply-To: <199910252120_mc2-8a6c-2...@compuserve.com> from 

Re: IEC 364 - Definition of SELV

[Rich Nute]

Hi Kevin:


>   Can anyone please provide the SELV definition from IEC 364?

I'm working from some old documents, but...

SELV is not expressly defined in IEC 364-4-41.  Instead,
it specifies "Protection by safety extra-low voltage."

It says:

"Protection against electric shock in normal service
and in case of a fault is deemed to be ensured when:

- the nominal voltage cannot exceed the upper limit
  of Voltage Band I*,

- the supply is from one of the safety sources listed
  in Sub-clause 411.1.2, and

- the conditions of Sub-clause 411.1.3 are fulfilled."

"*See IEC Publication 449: Voltage Bands for Electrical
  Installations of Buildings."

The safety sources are:

- a safety isolating transformer,

- a source of current providing a degree of safety 
  equivalent to that of the safety isolating transformer
  (e.g., motor generators with windings providing 
  equivalent isolation),

- an electrochemical source (e.g., a battery) or another
  source independent of a higher-voltage circuit (e.g., a
  diesel-driven generator,

- certain electronic devices complying with appropriate
  standards where measure have been taken to ensure that, 
  even in the case of aninternal fault, the voltage at the
  outgoing termainals cannot exceed the values specified in
  Sub-clause 411.1.1.

The definition of SELV appears in IEC 536:

"A voltage which does not exceed 50 V ac rms between
conductors, or between any conductor and earth, in a 
circuit which is isolated from the supply mains by means
such as a safety isolating transformer or converter with
separate windings."

IEC 950 defines SELV CIRCUIT:

"A secondary circuit which is so designed and protected 
that under normal and single fault conditions, its 
voltages do not exceed a safe value."


SELV is a special case of ELV, Extra Low Voltage.  ELV is
defined (or implied) as a maximum voltage value deemed not to 
cause an electric shock.  SELV applies to an ELV where, in
the absence of specific protective mechanisms, the ELV would
exceed ELV under fault conditions.  So, SELV implies ELV with
some means to prevent the voltage from exceeding ELV limits
in the event of a fault.

A single-insulated transformer ELV secondary is ELV.

A double-insulated transformer ELV secondary is SELV.

An ELV battery is ELV.  It may or may not be SELV, depending
on your point of view.  

1:  Since the battery itself cannot exceed ELV under single-
fault conditions, then it cannot be SELV.  Or, 

2:  Since the battery itself cannot exceed ELV cannot exceed 
ELV under single-fault conditions, then it must be SELV.  

However, as defined, SELV implies an included protective
mechanism to limit the voltage in the event of a fault.  SELV
also implies that the ELV is derived from a higher, non-ELV
source.

If you accept that a battery is ELV, then the safety standards 
require that the battery voltages cannot be touched!


Best regards,
Rich




-
This message is coming from the emc-pstc discussion list.
To cancel your subscription, send mail to majord...@ieee.org
with the single line: "unsubscribe emc-pstc" (without the
quotes).  For help, send mail to ed.pr...@cubic.com,
jim_bac...@monarch.com, ri...@sdd.hp.com, or
roger.volgst...@compaq.com (the list administrators).