The duration of test should not relate with derating of test voltage.
The purpose of dielectric test is to check for any insulation breakdown.
Like for production line test, it is allow to reduce the test duration to
1s, but it test at the same voltage as in 1 minute test
Cheng-Wee Lai
From:
I read in !emc-pstc that Gregg Kervill gr...@test4safety.com wrote (in
002b01c25428$4985b680$7100a8c0@MENHADEN) about 'electric strength
test' on Wed, 4 Sep 2002:
This would suggest that it would be better to
double/reinforce insulate the mains against
earth, in which case SELV could be earthed.
-Original Message-
From: owner-emc-p...@majordomo.ieee.org
[mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of Rich Nute
Sent: Tuesday, September 03, 2002 7:31 PM
To: soundsu...@aol.com
Cc: Product Safety Technical Committee
Subject: Re: electric strength test
Hi Greg:
Why
Hi Greg:
Why does True SELV require basic insulation
between SELV and earth?
What is the hazardous voltage source, and what
is the current path through the body if that
basic insulation should fail?
I believe (and I could be wrong) that it's a
On Sat, 24 Aug 2002 12:43:43 EDT,
soundsu...@aol.com wrote:
Why does True SELV require basic insulation
between SELV and earth?
What is the hazardous voltage source, and what
is the current path through the body if that
basic insulation should fail?
I believe (and I could be
In a message dated 8/24/02 2:08:10 AM Eastern Daylight Time,
j...@jmwa.demon.co.uk writes:
Why does True SELV require basic insulation
between SELV and earth?
What is the hazardous voltage source, and what
is the current path through the body if that
basic insulation should fail?
I
I read in !emc-pstc that Rich Nute ri...@sdd.hp.com wrote (in
200208232012.naa27...@epgc264.sdd.hp.com) about 'electric strength
test' on Fri, 23 Aug 2002:
Hi John:
True SELV . requires double or reinforced insulation from hazardous
live parts/parts at hazardous voltages [different
Hi John:
True SELV . requires double or reinforced insulation from hazardous
live parts/parts at hazardous voltages [different expressions used for
the same things] and basic insulation from earth. '950 SELV' allows SELV
circuits to be earthed (see 2.2.3.3 of IEC60950:1999 or
Group,
In Annex ZB to EN 60950:2000, under Clause 1.7.2, Norway has a marking
requirement for
Class I, Type A pluggable equipment (intended for connection of other
equipment) where the
safety relies on the connection to protective earth. The marking must
state that the equipment
is required
I read in !emc-pstc that Rich Nute ri...@sdd.hp.com wrote (in
200208222310.qaa20...@epgc264.sdd.hp.com) about 'electric strength
test' on Thu, 22 Aug 2002:
That depends on which variety of SELV you mean. True SELV, as opposed to
'950 SELV', requires double or reinforced insulation from
On Thu, 22 Aug 2002 21:42:34 +0100,
John Woodgate j...@jmwa.demon.co.uk wrote:
Pri to true SELV secondary doesn't pose a problem. The chassis is
irrelevant. For '950 SELV', there is no requirement for a pri-sec test
at any voltage above that for pri-chassis.
Really?
I thought primary -
Hi John:
That depends on which variety of SELV you mean. True SELV, as opposed to
'950 SELV', requires double or reinforced insulation from earth
Why?
Best regards,
Rich
---
This message is from the IEEE EMC Society Product Safety
Hi John:
Y-caps have enough margin to easily withstand
the 4300 V dc without damage.
Without immediate failure, no doubt. But such a huge overstress may
cause latent damage that later results in failure, and, since IEC 60384
doesn't call for such an over-voltage test,
Hi Brian:
What I've always wondered about, at least for class 1 construction, is just
what is really being tested by the pri/sec hi-pot, when the customer chooses
to ground the power supply's return.
(These comments presume the secondary is SELV.)
When you use a ground for safety
I read in !emc-pstc that Brian O'Connell boconn...@t-yuden.com wrote
(in f7e9180f6f7f5840858d3db815e4f7ad1f2...@cms21.t-yuden.com) about
'electric strength test' on Thu, 22 Aug 2002:
Also,as some of our output-to-chassis Y caps are just 100V decouple caps,
Y-caps are specifically for connection
I read in !emc-pstc that Tyra, John john_t...@bose.com wrote (in
418fbd441c22d5118d860003470d43160543e...@cupid.bose.com) about
'electric strength test' on Thu, 22 Aug 2002:
If you plan on selling in
this region you should check all of the National deviations and maybe
contact DEMKO (part of UL
I read in !emc-pstc that Peter Merguerian pmerguer...@itl.co.il wrote
(in 2D1037012914D4118DB8204C4F4F50203DD9CC@ITLLTD01) about 'electric
strength test' on Thu, 22 Aug 2002:
You may come across some distributors in Norway asking for DI or RI
between PRI-EARTH, even for Class 1 power supplies.
I read in !emc-pstc that Rich Nute ri...@sdd.hp.com wrote (in
200208221745.kaa19...@epgc264.sdd.hp.com) about 'electric strength
test' on Thu, 22 Aug 2002:
Y-caps have enough margin to easily withstand
the 4300 V dc without damage.
Without immediate failure, no doubt. But such a huge
Brian -
From what I can glean from your message, the equipment is
Class 1, but the secondaries do not rely on earthing for
SELV reliability (hence, the Reinforced Insulation EST
value). However, there appears to be some functional
earthing of secondary circuits or there would be no problems
for
...@bose.com]
Sent: Thursday, August 22, 2002 12:02 PM
To: 'Peter Merguerian'; 'Brian O'Connell'; emc-p...@majordomo.ieee.org
Subject: RE: electric strength test
I agree with Peter, per the standard, and most IEC product standards, you
need two levels of protection from electric shock. In your case the y
...@majordomo.ieee.org
Subject: RE: electric strength test
Brian,
Your interpretation of the standard and application of the test between
pri-sec is acceptable. You need to speak to a higher level person in the
agency who is an expert!
Please be advised that some countries do not have a reliable earthing
Brian,
Correction:
You may come across some distributors in Norway asking for DI or RI
between PRI-EARTH, even for Class 1 power supplies.
-Original Message-
From: Peter Merguerian
To: 'Brian O'Connell'; emc-p...@majordomo.ieee.org
Sent: 8/22/02 7:09 PM
Subject: RE: electric strength
Hi Brian:
I am attempting to comply with both the letter and spirit of 60950:2000, cl
5.2. Note that 5.2.2 allows for separate testing, according the type of
insulation required. When testing a (class 1) power supply, the withstand
level for primary to chassis is Basic; and for
Brian,
Your interpretation of the standard and application of the test between
pri-sec is acceptable. You need to speak to a higher level person in the
agency who is an expert!
Please be advised that some countries do not have a reliable earthing
system. Many end-product manufacturers design
I read in !emc-pstc that Brian O'Connell boconn...@t-yuden.com wrote
(in f7e9180f6f7f5840858d3db815e4f7ad1f2...@cms21.t-yuden.com) about
'electric strength test' on Thu, 22 Aug 2002:
A (new) agency engineer says that inserting a piece of insulator defeats the
purpose of the test.
I don't see
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