Mike:
There is no Federal requirement for the manufacturer to have
equipment listed or NRTL approved. The requirements are set by
localities, as Richard Woods clearly points out.
I can understand that in some companies, the powers-that-be
have little patience with the time and expense of
Hello Gary,
Sounds like your making a case
for the wider adoption of the UK
system with fused plugs rated
to protect the power cord
Nick Rouse
- Original Message -
From: Gary McInturff gary.mcintu...@worldwidepackets.com
To: EMC-PSTC (E-mail) emc-p...@ieee.org
Sent: Wednesday, October
Hi Gary:
Somewhere in my past, I've heard the rationale for
this conundrum. I'm just guessing here.
Power cords and similar mains devices are sized
based on rated load, and are not sized based on
fault-condition load.
The requirement should be that, under fault
conditions, the device is
Excuse a slightly peripheral question.
I always called it (an oily sort of brownish paper) Fish paper. I
assumed the name came from the use of fish oil to prepare it in
the 1800's. I see you are referring to it (is it the same thing?)
as fische paper. Is that what it is sold as? Was it invented
Well for example, I have just finished specifying what compliance re-testing
I am going to need to do on 4 different products whose power conversion
stages use IRF630's, IRF740's, IRF840's, and RFP50N06's, but the list goes
on and on. If you are using power FET's in power electronics, chances
Hi Mike,
I don't know if this will help but, CFR 29 Section 1910.399 subpart S.. is
where the NRTL'S hang their hats on this issue.
Good Luck
Joe
Josiah P. Burch
Compliance Engineer II
Andover Controls Corporation
300 Brickstone Square
Andover,Ma 01810
(978)-470-0555 x335
Gary,
It was always my understanding that house fuses/breakers were to protect
all the upstream stuff, e.g. service entry box, external transformers etc.
They cannot realistically protect downstream stuff, as they have no
knowledge of how much current is too much for a given appliance.
I agree with Paul's take. One of the trees in the forest is keyboards.
Do you have any keyboards attached to the DUT? I have personally seen
an instance where EFT was coupling to a keyboard cable and causing all
sorts of wierd effects.
I thought it was our design's fault, so I tried filtering,
I am NOT an expert in this field so I could likely stand some educating but
the following seem to me to be common sense:
1) Household circuit breakers protect household wiring - only. They prevent
wiring damage and fires. There is no practical way to provide breakers for
every different kind
From: Douglas Beckwith@MITEL on 10/24/2001 02:05 PM
Hi Peter,
My understanding of 60950 is that distance through insulation applies here
(0.4mm). I have never had this issue with CSA.
Regards
Doug Beckwith
Mitel Networks
Peter Merguerian pmerguer...@itl.co.il on 10/24/2001 09:38:19 AM
Hi Mike:
Can someone point me to a section in the NEC that says a piece of
RESIDENTIAL computer equipment must be listed (NEC definition). Article
645 which requires a listed piece of equipment appears to apply to a
computer room and not a residence.
In terms of the NEC, a
Dear Group,
I just was reading the a list to assist one in choosing one's class
designation under the RTTE directive at
http://www.europa.eu.int/comm/enterprise/rtte/listeq.htm
http://www.europa.eu.int/comm/enterprise/rtte/listeq.htm and I noticed
that there are items under Class 1 that I never
Bonjour de Montreal,
It all depends of the procedure you used for your product :
If it is a Class B digital device using the, now obsolete, certification
process, you have to put at a minimum the FCC ID of your granted
certificate. The only way it could be used now is by the mean of a
permissive
Peter,
my experience is, that you will not receive a statement from the
manufacturer of the capacitor about the foil around the cap. This would be
required to proof, that it is good for basic insulation.
Our company (we are a GS-mark certification body) does not accept the foil
around a
I asked a similar question a couple of years ago, and was told that the
bodies of plastic encapsulated Y1 capacitors are considered by CENELEC to be
reinforced insulation, except in the vicinity of the leads. I don't know if
this extends to types of X and Y caps other than Y1.
Hope this is
Hi all,
Some companies make through-hole polarized caps which cannot be loaded
backwards; they are 3 pin in-line parts that are assigned +/-/+. Does
anyone make SM parts that have the same attribute of not capable of being
loaded backwards?
Also where may I find reliability data for the so
Mike, regardless of what the NEC says, and it is not very clear in this
regard, it is the state, county and city electrical codes and other local
regulations that apply. Many jurisdictions have deviations from the NEC
and/or have other regulations that require electrical equipment sold to the
Fuses and breakers etc, are provided to protect the wiring
downstream from these devices. A 15 amp breaker is allowed to have 14 AWG
wire attached and run all though my house, and terminates in a 15 amp rated
receptacle - parallel blade with ground pin.
Why then can I plug in a
Can someone point me to a section in the NEC that says a piece of
RESIDENTIAL computer equipment must be listed (NEC definition). Article
645 which requires a listed piece of equipment appears to apply to a
computer room and not a residence.
Basically I've been asked where its says a piece of
Our company manufactures switching power supplies to EN60950 and EN60601-1
standards, and our safety group looks for these issues.
In fact, I got 'bit' by that same problem last week. Spacing was OK when the
PWB was mounted in the chassis, but when the cover was installed, it failed
It's over on Bizarre Street.
At 10:33 AM 10/24/2001 , Cortland Richmond wrote:
telephone products destroyed by all sorts of bazaar events
Where IS that bazaar? (grin)
Cortland
---
This message is from the IEEE EMC Society Product Safety
Technical
Alex, make sure you investigate whether or not energy is coupling to other
cables of the EUT and causing problems. In other words, try to reduce the
system (remove cables) and see if the EFT failures persist. If you can't
remove a cable due to functionality, place ferrites on it instead (near
telephone products destroyed by all sorts of bazaar events
Where IS that bazaar? (grin)
Cortland
---
This message is from the IEEE EMC Society Product Safety
Technical Committee emc-pstc discussion list.
Visit our web site at:
Dear All,
I have submitted an ac input to dc output switching power supply for NRTL
approval. One deviation is that the primary ac insulated capacitor is too
close to the earthed chassis and that the insulation cannot be relied to
provide the required basic insulation.
1. What is the group's
Thanks Joe - that was the very point that I was trying to make - and that is
why TNV is treated as hazardous.
-Original Message-
From: owner-emc-p...@majordomo.ieee.org
[mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of j...@aol.com
Sent: Tuesday, October 23, 2001 10:44 PM
To:
Dear all,
The product concerned is a metal box located on the (metal) roller bridge of a
crane and controls the movement of that bridge.
It is powered by min. 48Vac and receives commands from an operator with a
battery powered hand-held radio transmitter command box.
The 48V ac power supply
Hi EMC members.
I have a question about Fcc Label.
This model is too small to insert Fcc verification statement on device.
This is Compactflash memory card.
I read Fcc Part 15. rules but I couldn't understand meaning.
On Section 15.19 said "alternatively,shall be placed on the
Alex,
What happened during the burst test ? Did the EUT break down or did you only
have minor disturbances/faults during the test ?
I assume that you know that EFT/bursts usually is a performance criteria B
test, which means that temporary faults are accepted during the test, as
long that the
Hi Cecil,
You're coming up with a good question, but could you be more precise what
you are looking for ? Limits? EUT configuration ? Measurement equipment?
. You name it! EMC above 1GHz could fill serveral pages
Best regards
Amund Westin, Oslo/Norway
-Opprinnelig melding-
In a message dated 10/23/01, Gregg Kervill writes:
Have lines ever been struck by Lightning?
One of my clients had a cupboard full of telephone products destroyed by
all sorts of bazaar events - like the temporary three phase power line to a
factory that fell' across domestic phone
Have lines ever been struck by Lightning?
One of my clients had a cupboard full of telephone products destroyed by all
sorts of bazaar events - like the temporary three phase power line to a
factory that fell' across domestic phone lines
Anything outside must be considered hazardous and
No takers? I haven't had any responses, but I can't believe that ins't an
issue for many of you. The switch-mode power supplies used in almost all
equipment these days are the main users of these FET's, and the FET design
change does effect compliance.
Have none of you run into this issue?
We are looking for a good failure analysis company in the SF
Bay area. Anyone have any leads for companies you've had a
positive experience with?
Regards,
Peter L. Tarver, PE
Product Safety Manager
Sanmina Homologation Services
peter.tar...@sanmina.com
Hi Cecil,
You're coming up with a good question, but could you be more precise what
you are looking for ? Limits? EUT configuration ? Measurement equipment?
. You name it! EMC above 1GHz could fill serveral pages
Best regards
Amund Westin, Oslo/Norway
-Opprinnelig melding-
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