Sam,
I have not heard of semiconductors that are required to have this. However,
I know there are manufacturer's of metal-oxide varistors (MOVs) that are
incorporating this due to adverse failure conditions that can occur at the
components end of life or because of a temporary over-voltage
Chris,
As a manufacturer of surge protection devices, I can relate to what you have
experienced. In the safety testing of the design, a hi-pot is performed to
without the surge components to ensure a good design.
In product, we have three different requirements from our safety agencies
(UL and
Mark,
I think it depends on the tests that are being conducted and the amount of
degradation that this may cause to the equipment. If testing for emissions,
I would think in general that there would be no issues. When testing for
susceptibility, that may be a different issue, especially if the
This scenaro comes up often in our designs. We typically use 0.010 or 0.020
inch thick Nomex (vulcanized fiber) instead of plastic. The Nomex is UL
recognized, 94V-0, very low cost and can be bought in sheets or punched to
the exact size.
Thanks,
Bryan.
From: drcuthb...@micron.com
To:
There are numerous standards in the market that address surge voltages
associated with the environment and associated test documents.
Some standards are:
IEEE C62.41
IEEE C62.37
IEEE C62.42
Test Documents are:
IEEE C62.45
NEMA LS 1-1992
IEC 61643-1
IEC 61643-12
UL 1449
UL 497
While most of
Paolo,
I am not aware of a commercial or EN standard for more than 16 amperes.
There are some military standards that also address this. The one that I
have seen in the past was MIL-STD-704.
From a product specification perspective, the customer or company can create
a standard calling many
I to responded to the organization and have yet to hear back. However, mine
request was only a few days ago.
Bryan.
From: Scott Barrows
To: Peter L. Tarver; 'emc-pstc'
Sent: 7/2/03 11:38 AM
Subject: Re: NARTE safety engineer certification
Hi Pete,
Funny you should mention that - It has been
There have been some good tips on checking UL compliance. Every PWB that is
UL recognized needs to be stamped with the company name (or mark) and the
style of marking of the rating, 94 V-2, 94 V-0, etc. One way that we check is
by using UL's web site. Here is the link to where you can search on
Ged,
After a little research, I found some history of the CBEMA/ITIC curve. This
was developed by the CBEMA's ESC-3 Working group to provide information for
the IEEE STD 446 (Orange Book). Within the Orange Book, I have the 1987
edition so there may be some changes, section 3.11 - Data
Richard,
This power system is denoted as a 3-phase delta high leg. It is an older
distribution system and is derived from a 240 vac, 3-phase delta, 3W+G.
Basically, what they have done is center tapped one of the 240 volt windings
and anchored that to ground. This gives 120/240 for standard
Chris,
Most MOVs are rated as 'Y' components. The manufacturer should be able to
point you towards the appropriate agency information. You should also be
concerned about the overvoltage affects of MOVs. Without some sort of
thermal protection these devices can be very destructive. But, you
From my experience, Mexico has recognized our UL Listing and CE compliance
documents, with the weighting factor being towards UL.
Thanks,
Bryan Cole
Director of Engineering
Product Safety Officer
Liebert / Control Concepts
Binghamton, NY
-Original Message-
From: Barker, Neil
To:
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