At 11:58 AM 19/08/1999, Brent DeWitt wrote:
A question for the safety folks (I'm more EMC oriented).
As of Jan 01, 2000, there will be a new CSA mark with a C and a US under
it indicating testing to both countries requirements. Does anyone know if
the local regulatory folks (fire marshals,
You should always start at the lower ESD Level and step up to the higher
levels. You cannot skip the lower levels as I have encountered products
that pass the higher levels and fail at the lower levels.
Pryor McGinnis
c...@prodigy.net
-Original Message-
From: Jim Hulbert
Hi Egon,
Gee, I'm glad the list found you. I was really worried for a moment... ;)
I checked out the CENELEC decision website and found it to indeed be missing
the EN60950. Could I infer from this that there have been NO
decisions...nyet! The site looks like it could use some tender loving
--- Benoit Nadeau bnad...@matrox.com wrote:
Bonjour de Montreal,
In another life, I was working for a EMC Test lab
and we always used the
step by step procedure which was in the ESD
Standard. We tested using this
procedure for years and we did encounter some
products who failed at low
CSA is fully accredited by OSHA as an NRTL and their mark is just as
acceptable as UL, ETL, WYLE or any of the U.S. based NRTL's. The fundamental
requirements for Listing described in the National Electrical Code NFPA 70,
do not specify UL only.
Article 90-7 Examination of Equipment for Safety
I agree that you should test and progressively increase the levels, because
the lower level tests pre-condition the samples and if you fail then you
have already obtained the data to apply the highest passing level. This is
even more important when you are doing more destructive tests like TOV.
This is just a modification of an existing scheme, the CSA mark with
NRTL/C under it. The old NRTL and new US designations are both
indications of the same thing: CSA's status as an NRTL with OSHA, and
the use of the applicable US standards (in other words UL standards) in
the evaluation of the
I concur, particularly with item 2. It is my understanding that the
frequency spectra is different at the lower levels. Meaning your are
stressing different frequencies. Not sure I fully understand why, if the
discharge waveform is described shouldn't it be the same rise time for all
voltage
To all members of this distinguished group. I now come to you not to make
commitment but to ask your for help.
My situation is this; I had an OATS site to which I wanted to add a 3 Meter
chamber (ETS Model 20) for Immunity test per the EU requirements.
I started this quest in 1997 and have
A question for the safety folks (I'm more EMC oriented).
As of Jan 01, 2000, there will be a new CSA mark with a C and a US under
it indicating testing to both countries requirements. Does anyone know if
the local regulatory folks (fire marshals, etc) in places like Chicago and
L.A. are in full
We also fully test at each lower level up to the one we need to pass. It is
time consuming, but that is what the standards call for, and that is what we
do. I don't want to have to explain to some AHJ some day why I didn't follow
the test procedure. Typically, we test our equipment, in-house, to
Jim,
You have been doing right thing. Those who directly go to the highest ESD
voltage level may thought if DUT can pass the highest level it will certainly
pass lower level. As a matter of fact, DUT could possibly fail at lower level
and pass at higher level. Because DUT got larger current
Se section 15.31(f)(1) of CFR 47. This section allows extrapolation.
Bob
==
Steve Kuiper aegisl...@email.msn.com on 08/19/99 09:48:11 AM
Please respond to Steve Kuiper aegisl...@email.msn.com
To: EMC-PSTC
In another life, I was working for a EMC Test lab and we always used the
step by step procedure which was in the ESD Standard. We tested using this
procedure for years and we did encounter some products who failed at low
level ESD but had no problem at higher levels.
We wondered what to conclude
For both tests (and EFT), we go from the lowest and step through to the
higest level specified by the standard or our customer. I have had
equipment pass a given voltage and fail at a lower voltage level, but I
have only seen this happen with ESD (not EFT or surge).
Jim,
Here at Emulex we also start at the lowest test level and slowly work our
way up. In my time working at a commercial test lab, I have seen several
cases where a product could fail ESD testing at 6 kV but pass at 8 kV. We
step through all of the levels as required by the test procedure
Hello, folks,
I have another problem here to calibrate a
3-port waveguide coupler.
Remember I posted a question regarding
return loss measurement several days ago.
I appreciate UKAS has agreed with our
setup since we provided scientific error
model of the setup and initial derivation
of the
Dear Colleagues,
I am working to grasp the implications of the PED (Pressurized Equipment
Directive) for our equipment.
I have managed to wade through the articles and determine which Annex II
tables I should be concerned with.
I'm stuck on determining the DN value for tubing in our equipment.
Jim, I believe you are correct, especially for the tests according to EN
61000-4-2 and EN 61000-4-5, (ESD Surge). The tests should be done at
lower voltages. We have always done it that way at TUV Rheinland. By the
way, for the surge tests, following the standards and doing all the lower
Art,
You absolutely win the prize for the first truly definitive answer to my
challenge! Obviously Mr. Blocher had the same trouble interpreting the
meaning of utilization equipment. Note how simple it was for OSHA to
clearly state that desktop computuers (PCs) are included. It is a shame
Hi Jim,
You are absolutely correct.
Many clients want to know at what the threshold level the E.U.T.
exhibited degradation
before/or component failure. Don't forget about EN61000-4-4 Electrical
Fast Transients
Best Regards
-Original Message-
From: Jim Hulbert [mailto:hulbe...@pb.com]
Hello George,
While I'm reluctant to flog a dead horse, somewhere along this discussion
thread, someone was looking for a definitive statement regarding the
subject at hand. After searching OSHA's Interpretation Letters I found
the following letter relating OSHA's requirements and (desktop)
Bonjour de Montreal,
In another life, I was working for a EMC Test lab and we always used the
step by step procedure which was in the ESD Standard. We tested using this
procedure for years and we did encounter some products who failed at low
level ESD but had no problem at higher levels.
We
Hi Bill,
No, I haven't disappeared. As desirable as the thought may seem, it's not
that easy to get rid of me.
:-)
Regarding the Cenelec's List of Decisions, yes, I have cancelled my home
page. Wasn't really using it (too busy with my day job), so it was a bit
of a waste of money.
In
Jim,
The way you use to perform the tests is the right one. We use exactly the
same one.
In France too, some labs are testing as you explain, but they are wrong.
good work !!
==
Pierre Selva
Laboratory
Bob,
I agree with you.
On the list we take off company hats and try to resolve issues: just keep to
facts and life will only get better for everyone.
Soapbox mode OFF
Derek Walton.
-
This message is coming from the emc-pstc discussion list.
To cancel your subscription, send mail to
Try his Have Modem Will Travel address
eva...@csi.com
-Original Message-
From: owner-emc-p...@majordomo.ieee.org
[mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of Bill Lyons
Sent: Thursday, August 19, 1999 2:54 PM
To: mail2n...@news.news.demon.net
Cc: emc-p...@ieee.org;
Moreover,
The FCC clearly states in section 15.109 of the CFR 47 that the measurement
distance for a class A device is fixed at 10m. I don't see where there is
any room for interpretation as to the distance between the EUT and antenna.
Obviously, labs cannot test to 10m in an FCC approved 3m
Tania,
Thank you for your comments. Allow me to better explain my position.
1. I am well aware of the language you cited from UL1950. This has
never been in question, as it is precise and understandable. Page
23? even lists many examples of products falling under the standard.
2.
By cutting off discussion of this topic, you have allowed untruths to be
perpetuated about 3 meter semi-anechoic chambers and have left the readers
of this list server with the impression that 3 meter chambers are to be
viewed as outlaw test facilities.
You have done a great disservice to the
Immunity test standards EN50082-1:1997 and EN 55024 call out the basic standards
EN61000-4-2 and EN61000-4-5 for ESD and Surge.
EN61000-4-2, Section 5 starts out The preferential range of test levels for the
ESD test is given in table 1. Testing shall also be satisfied at the lower
levels
Hi Bill,
The CENELEC CTL Decisions you seek are now (officially located and
maintained) at:
www.imq.it/ctldecisions/
Although still under construction, the site is already a valuable
resource as it is indexed by Standard, Product Type, etc.
NOTE: I believe that CTL decisions serve as
Friends,
As you may know, I maintain the sci.engr.electrical.compliance (SEEC)
FAQ. I was recently alerted by Richard Steele r.ste...@ftel.co.uk
that the link in section 2.4 Cenelec's List of Decisions
http://www.varju.bc.ca/standards/ no longer exists.
On further checking, I found that Egon
To all us others, and primarily to George at Lexmark!
Regarding your item 3. The NEC and OSHA requirements probably do apply
to any electrical device that is operated from voltages above SELV.Take
a look at the 3rd edition of UL1950 under Scope, 1.1.1: This standard is
applicable to
Steve,
FCC does not certify any test sites;-- they merely accept your site's
description, photographs, attenuation measurements, antennas used for
testing, etc., to make sure you have done due diligence to the
requirements. They then provide this list of available commercial sites to
the
Apparently these power supplies are hard to find.
I may be slightly off the track here but we designed some a couple of years
ago (up to 1000 Watts) using Microlinear Power Factor Regulator Chip ML
4812. It featured a boost buck configuration. We got efficiencies of up to
88 % using powdered
My experience has seen that the FCC will allow a chamber to be used if
enough data has been taken (i.e. 900 points) and with a statement like: [If
challenged the decision with be settled at an Open Air Test Site.] Now I do
not know if you have to own the OATS or use another labs, I don't think it
Hello from San Diego:
Please respond privately to Steve on this topic.
We all need to protect both ourselves and the IEEE
from possible libel or slander.
If you want to discuss this request, please contact
me privately.
Thanks, and best regards,
Richard Nute
co-administrator, IEEE
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