Chris,

You state:

"Another point I wanted to bring out we had a product tested to CSA
approvals.  Inside, we used a power supply that carried a UL listing with "C
US" subscript which said that UL tested it to both UL and CSA standards.  A
copy of the test report wasn't enough for CSA.  Since UL did the testing,
they wanted construction details.  The manufacturer that we wanted to use
refused to provide them (I have to agree on this one.)  This left a very
sour taste in my mouth regarding the whole "C US" dual approval issue.  What
is the point of UL providing a "C US" lising if CSA treats it as if it means
nothing?"


Yes, UL and CSA unfortunately are the only organizations who would like to
see their country standards covered by their own laboratories. That means
CSA will accept a UL Recognized component when they investigate a product to
UL standards but will not accept a UL Recognized component when they
investigate a product to CSA standards. Same goes for UL; they will acccept
a CSA Certified component when they investigate a product to CSA standards
but will not accept a CSA Certified component when they investigate a
product to UL Standards. 

When I asked noth organizations why they do this: they responded that their
MOU covers acceptance of the test results but not the follow-ups. This is
why each would ask for the complete construction details so that they can
cover the components and make money off follow-ups.


Regards



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





-----Original Message-----
From: Chris Maxwell [mailto:[email protected]]
Sent: Thursday, September 26, 2002 6:34 PM
To: [email protected]
Subject: RE: subcontracted parts - compliance with EN's



Just a couple of notes from experience.

We once used an open frame power supply without previous certification.  It
was done as a custom design because we needed AC or 12VDC operation.  We
found a small company that would do such a design (very interesting
transformer by the way...AC primary, 12VDC primary, two secondaries, a
bootstrap)

Anyway, we were only interested in CE marking (not UL/CSA) so we simply had
the design reviewed and tested with our product.  As for continuation, it
was a custom part; so we added the compliance requirements to the part
specifications.  Yes, I know this doesn't give us complete control; but it
does put the responsibility on the correct shoulders. We take responsibility
for the product; and we did the testing.  But it is up to the supply
manufacturer to ensure that he uses the parts specified in the test reports.
Our company paid for the testing and we shared the test report information
with the manufacturer.  So the only guarantee is the manufacturer's
integrity.

The main downfall of this approach was that I became the middle-man between
the supply manufacturer and our test lab.  One benefit of this approach is
that it shortened design time.  We didn't have to wait for the supply to be
designed and tested; then integrate it into our test sample for a re-test.
Everything was tested all at once.

Some may say that this isn't as good as a supplier who gets audited by UL or
CSA; but I would argue that a supplier's integrity along with hipot/ground
bond testing on your finished product are the most important aspects of your
compliance program.  Even if a manufacturer is audited by UL or CSA...they
won't go to bat for you if there is a lawsuit.    You're still only left
with supplier integrity as your defense. 

Another point I wanted to bring out we had a product tested to CSA
approvals.  Inside, we used a power supply that carried a UL listing with "C
US" subscript which said that UL tested it to both UL and CSA standards.  A
copy of the test report wasn't enough for CSA.  Since UL did the testing,
they wanted construction details.  The manufacturer that we wanted to use
refused to provide them (I have to agree on this one.)  This left a very
sour taste in my mouth regarding the whole "C US" dual approval issue.  What
is the point of UL providing a "C US" lising if CSA treats it as if it means
nothing?  Anyway, that isn't the issue...I wanted to bring out two points 

1.  There is occasionally an argument for using a power supply that doesn't
have previous approvals.

2. Power supplies with previous approvals still don't guarantee a smooth
ride through agency testing...especially when you get caught in the middle
of a "posturing" contest between the agencies.

If my message doesn't help clear the water; I hope it at least helps you
figure out where some of the mud came from :-)

Chris Maxwell | Design Engineer - Optical Division
email [email protected] | dir +1 315 266 5128 | fax +1 315 797 8024

NetTest | 6 Rhoads Drive, Utica, NY 13502 | USA
web www.nettest.com | tel +1 315 797 4449 | 






> -----Original Message-----
> From: Brian O'Connell [SMTP:[email protected]]
> Sent: Thursday, September 26, 2002 9:50 AM
> To:   [email protected]
> Subject:      RE: subcontracted parts - compliance with EN's
> 
> 
> CONFLICT OF INTEREST NOTICE:
>       My employer makes componet power supplies (almost all types).
> 
> I was waiting for someone (Mr Woodgate?) to jump on this...
> 
> I can think of no reason to ever build in a component power supply, that
is
> connected to mains, or a safety-related TNV source, that does not have an
> existing CB report and/or a major agency approval. There is no way that
you
> can demonstrate control of the construction of a power supply unless the
> vendor is subject to FUS audits by the applicable agency(s).> 
> 
> A (CE-type) declaration of conformity does not prove anything.
> 
> You do not need construction details for a recognized power supply, your
> agency engineer will be the "escrow agent" for the CB report. My complany
> routinely provides copies of our CB report to agency engineers. We seldom
> provide detailed construction data to a customer, unless it is a custom
> power supply. Get a copy of the installation instructions, a copy of the
CB
> and safety agency certs, and you are done...
> 
> I do not speak for my employer.
> 
> R/S,
> Brian
> 
> 

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