1) Correct, this cannot be used in a multiwire branch circuit since it
may eventually be removed without being bypassed. The concern is that an
open neutral in a multiwire (e.g. 120/240 3w or 120/208 4w) circuit
leaves loads connected in series phase to phase. The voltage across a
product intended
I'm no medical Guru either but I know the sort of field levels involved.
They range from about .5 to 3 teslas. This is not much higher
than the fields in the gaps of electrical motors and generators
(up to 1.8T in normal silicon iron and up to 2.1 T in cobalt
iron used in aerospace machines)
We are facing the same challenge.
The way we address it is essentially the TCF route, including a Competent
Body involvement.
Our installation contains some equipment qualified for residential
environment only, which wouldn't meet the industrial immunity test levels by
itself. We add filters in
I would amplify on my original MOTO response and say that it is common
practice to scan using peak detection, and use average detection only at
frequencies where an outage condition occurs; that will drastically reduce
test time.
--
From: Gert Gremmen g.grem...@cetest.nl
To: Ken Javor
At ce-test, we call this kind of answer EOE - Evidence by Experience,
in addition to MOTO, the dwell time should extend any slow variations
that EUT emission contains
A fine and obvious example is the Microwave oven: emission varies
substantially with the rotation degree of the food rotating
I read in !emc-pstc that Robert Wilson robert_wil...@tirsys.com wrote
(in 3FF57405336C9B4C976A1819F860A2560F698D@xng_tirsys.TIRSYS.COM)
about 'Power Factor regulations.', on Tue, 30 Apr 2002:
We will be starting the design of a relatively simple, off-line
switchmode power supply that will be
I read in !emc-pstc that richwo...@tycoint.com wrote (in 846BF526A205F8
4BA2B6045BBF7E9A6A01F140FA@flbocexu05) about 'General Product Safety
Directive', on Tue, 30 Apr 2002:
Now, back to the original question. I found the following definition of
professional apparatus in EN 55103-2 (immunity for
I have a general question regarding power factor limits relating to the
design of off-line switchmode power supplies.
We will be starting the design of a relatively simple, off-line
switchmode power supply that will be used to power an LED Luminaire (for
lighting up the outside of buildings). A
I have a couple of questions regrading the National Electrical Code:
1) Consider a power measuring device that is intended to be installed into
a residential 120V branch circuit, protected by a single 15 A or 20 A
circuit breaker. The device would be installed into a conduit outlet box
on
Well, this series sure took a left turn and accelerated hurriedly out of
site of the original intent which was to determine what the term consumer
means as used in the GPSD. The imaginary product example I put forth was
intended solely to support the question, and I in no way advocated that such
You have me all confused here. You claim the equipment should be able
to state heavy industrial immunity but at the same time acknowledge that some
of the components don't meet the surge requirements. Kind of like the
government saying fiscal responsibility - an oxymoron.
If
Hi Amund,
I read your email (below). I'm no medical device expert; but I'm
wondering if the magnetic strength limit was set so high due to MRI
(Magnetic Resnonance Imaging) devices. My understanding is that MRI
devices produce HUGE magnetic field levels. According to a recent
newspaper story
How do the safety standards (for example, IEC 60950 and their clones) define
'insulating tape'?
Are the insulating properties determined as applied in the end product by hipot
and leakage current?
On Mon, 29 Apr 2002 12:16:16 -0700 (PDT), Rich Nute ri...@sdd.hp.com wrote:
Thanks for sharing your
Robert - I know that it may SEEM heavy but there is not NEED to go overboard
- do you remember the incident where a (Lithium) battery was 'charged' as a
result of a fault condition? The FAA banned all Lithium batteries in
aircraft for many years after the incident. Have you not mentioned any
At NASA we call this kind of answer MOTO - Master of the Obvious, but I
can't think of any reason the dwell time would be other than the longer of
the detector time constant or a small integer multiple of the broadband
spike repetition period.
--
From: Gordon,Ian
John is absolutely correct - an experienced engineer can run through '950
with a product in a couple of hours AND record WHY the various clauses and
entire sections are not applicable to a simple product.
I certainly would not intend to spend more time than that on something
simple - HOWEVER -
I read in !emc-pstc that Gordon,Ian ian.gor...@edwards.boc.com wrote
(in E1BA0362B28ED211A1E80008C71EA30601818F4F@EXC_EAS01) about 'CE
MARKING A SYSTEM', on Tue, 30 Apr 2002:
Can anyone advise the course of action in applying a CE mark as regards EMC
to a system some of whose component parts are
Gordon, cosider constructing a Technical Construction File (TCF) and
submitting it to a Competent Body. Your product may comply with the
essential requirements when operating in its intended environment without
the need to apply the full industrial strength tests. At least, you could
make that
Can anybody advise as to what dwell time should be used for an average
detector when measuring a broadband noise source? This time obviously
increases the total test time unnecessarily if set too high and reduces the
measurement accuracy if set too low.
Thanks
Ian Gordon
Can anyone advise the course of action in applying a CE mark as regards EMC
to a system some of whose component parts are not built by us and whose D of
C's claim light industrial immunity. However, the system has been running in
very harsh environments e.g. plasma etch applications at customer
Hi all,
I believe you have to apply C-tick mark to fulfill australia EMC
requirement. Do any one could tell me which AS standard and procedure
applicable to Battery toy that has motor and PCB circuit?
Thank you
Steven
QA Engineer
Tiger Electronics Far East Ltd.
On Wed, 24 Apr 2002 13:44:34 -0700, Doug McKean wrote:
For those interested in how to track down something like this,
take a look at the header information. You'l see a bunch of
Received: xx lines.
Lots of tricks involved here, including possibility of forged
headers. Those interested
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