IEEE 519 is a Recommended Practice. It suggests voltage distortion limits at
the Point of Common Coupling based upon the customer load vs short circuit
current capabillity. It has nothing to do with paroduct harmonics. It is not
a regulation, but electric utilities may adopt it as a company
Rick,
Chomerics' Springline product line is an off-the-shelf solution:
http://www.chomerics.com/products/cardcage.htm
The spring-fingers on these one-piece gaskets are formed
toward the rear panel instead of toward the inside, where
damage due to snagging can be a problem.
The only
What you got is exactly as stated in their specification.
http://www.tripplite.com/products/product.cfm?productID=228
- Original Message -
From: j...@aol.com
To: emc-p...@majordomo.ieee.org
Sent: Thursday, August 29, 2002 10:21 PM
Subject: Curious about Tripp-Lite isolation
As you mention, there can be common mode to differential mode conversion at the
service entrance since safety ground and neutral are tied together at that
point. This will come right through the transformer to some extent. But you did
mention that the transformer has a capacitor and MOV from
Oooops,
my reply was really relevant to Compact PCI panels, not
PCI. Sorry, I just realized it.
I haven't worked on designs using PCI brackets for EMC.
I believe that former Instrument Specielties, now part
of Laird Technologies, can help you. They are very
knowledgeable in the area of
John:
Re the US: Is IEEE519 given force in any way? Is there any agency, body,
or utility that is requiring IEEE519 compliance?
Re Japan: Do you know the name/number of the trial standard and where I
can find a list of what types of products it applies to?
Thanks,
Jim Eichner, P.Eng.
Joshua: Re Japan, I didn't have much luck on the JEITA website. Can you
give me a specific reference (standard name/number, URL, etc.)? Also, is
there a list of what types of products this requirement applies to?
Thanks,
Jim Eichner, P.Eng.
Manager, Engineering Services
Xantrex Technology
There are several types of gaskets. The ones with a
continuous ridge along the centerline (inverted V-shape)
are not compliant thus they can leave slots and cause
difficulties with board insertion. The spiral gaskets
make good contact but tend to kink, get caught and fall
out of the groove
I read in !emc-pstc that Luigino Catello luigino.cate...@tin.it wrote
(in 00a301c25046$2158dd80$be5dabd4@oemcomputer) about 'R: Telephone
headsets' on Fri, 30 Aug 2002:
The safety standard is the EN 60950.
Why? A telephone headset is not within the scope of EN 60950, I think.
EN 60065 is more
Yup, we had the same problem on a GNIC card. We made the card and its
L-shaped bracket. The card was intended for any ol' computer. The casual
contact between the face of the bracket and the PC chassis was iffy at best.
I put a couple of small dimples (punched slots really), on the
I read in !emc-pstc that Chris K. Poore chr...@percept.com wrote (in
kgeakhgkelfiikpbjhaiaejnccaa.chr...@percept.com) about 'Telephone
headsets' on Fri, 30 Aug 2002:
Is there a safety standard that we should use that is specific to these
telephone headsets for EU compliance?
What is the
I read in !emc-pstc that Michael Jang mich...@certitek.com wrote (in
poeoldooigidlejlplfpoejfcjaa.mich...@certitek.com) about 'I wonder
about some comments in IEC 664-1:1992' on Fri, 30 Aug 2002:
I don't have a standard (IEC 664-1:1992).
That says it all, doesn't it. The current edition is
Actually, the rule (Article 210-22 of the NEC) has nothing to do with
protecting the plugs or the wiring. The 80% rule is there to make sure the
branch circuit overcurrent protective device (fuse or CB) doesn't overheat.
- Original Message -
From: Robert Johnson john...@itesafety.com
In a message dated 8/30/2002, Don Borowski writes:
But there is common mode supression (hot and neutral against safety ground)
offered by the transformer, assuming that the capacitive coupling between
the
primary and secondary is minimal.
...There is one effect of a long run of bundled
For your telephone headsets you have to follow the RTTE directive not the
LVD.
The safety standard is the EN 60950.
L. Catello
Compliace Engineer
ITALTEL-Italy
- Original Message -
From: Chris K. Poore chr...@percept.com
To: EMC-PSTC emc-p...@majordomo.ieee.org
Sent: Friday, August
Chris, the CE marking indicates that the product complies with all
applicable directives. The only two directives that might apply is the LV
and EMC directives. However, the LVD does not apply since the working
voltages are low. The EMC directive would apply if your equipment is likely
to cause
Hi all,
Assume you are going to power three units from a power distribution box.
You might have two scenarios:
1. Route one cable to the first unit, from that unit you route a new power
cable to the next unit, and so on (serial connections)
2. Three separate power cables, one cable to
Mark Gill asked:
I have a question for the group on the effects of temperature rating and
deterioration. If a pcb is rated X degrees C, and the sizing of the power
traces on an inner layer is such that the pcb temperature is now (X-1)
degrees C,
What effect does this have on the longevity of
1. What is the correct method to test for a Limited Power source in
determining what enclosure is required?
The Isc limits must be met regardless of the load,
not only at 30a or 8a. You need to do sufficient
testing to satisfy yourself it will comply in general.
I am fighting the age old problem of PCI brackets on various PC chassis not
making adequate electrical contact. Aperture leaks, especially at high
frequencies, is a continual problem, to say nothing about the flimsy
construction of the brackets. Has anyone had any success with the clips,
Joe-
I think you have got most of the points right.
But there is common mode supression (hot and neutral against safety ground)
offered by the transformer, assuming that the capacitive coupling between the
primary and secondary is minimal. Note that this common mode signal is in fact
The transformer generates what the code call a separately derived
system. Typically such circuits are grounded (earthed). For US
requirements see the National Electrical Code articles 250.21 and
250.22. The isolation transformer reduces common mode (supply vs ground)
noise. That is its primary
In a message dated 8/30/2002, Chris Maxwell writes:
Most isolation transformers have a non-magnetic, metal shield between the
primary and secondary. The shield does not appreciably degrade the
transformer's magnetic coupling at 60Hz; however, it does attenuate the
high frequency
We have some telephone headsets that we want to CE Mark, but are not sure
what safety standard to use. Additionally, I don't see any category under
the CE Marking directive that would be entirely applicable. The LVD seems
most logical, except that the input voltage to the headsets is well below
Joe,
Most isolation transformers have a non-magnetic, metal shield between the
primary and secondary. The shield does not appreciably degrade the
transformer's magnetic coupling at 60Hz; however, it does attenuate the high
frequency differential noise passed from primary to secondary.
The
Alex,
1. What is the correct method to test for a Limited Power source in
determining what enclosure is required?
Peter: The correct method for inherently limited power source is to measure
the output current (Isc) after 60 seconds of operation with the load
adjusted to maintain the Isc
THE 2003 IEEE INTERNATIONAL SYMPOSIUM
ON ELECTROMAGNETIC COMPATIBILITY (EMC)
Istanbul Hilton Hotel, Istanbul, Turkey, May 11-16, 2003
Dear colleagues and fellow EMC engineers, Hello from Turkey,
We take great pleasure in inviting you to participate in the 2003 IEEE
International
Symposium on
Safety Folks -
I have a question for the group on the effects of temperature rating and
deterioration. If a pcb is rated X degrees C, and the sizing of the power
traces on an inner layer is such that the pcb temperature is now (X-1)
degrees C,
What effect does this have on the longevity of
On Tue, 27 Aug 2002 10:55:57 -0400,
richwo...@tycoint.com wrote:
Is JIS C 6861, mechanical standard for plastic fiber optic cable, the same
as IEC 6079-2?
JIS C 6861 says that it was written with the intention to make
it harmonized with the requirements of IEC 60794-1.
I'm not sure if
I read in !emc-pstc that John Allen ja014d7...@blueyonder.co.uk wrote
(in 048001c24f9d$bd8895a0$0200a8c0@johnallen) about 'Electric Fence
Controllers' on Thu, 29 Aug 2002:
I once (about 12 years ago) had the dubious priviledge of being the Comittee
Secretary for the UK BSI standards committee
Dear members
I don't have a standard (IEC 664-1:1992).
But, I wonder about some comments in IEC 664-1:1992 as below;
1. What does mean R.I.V. (Rated Insulation Voltage)?
Is it working voltage or EUT's rated voltage?
If it is not... hm please explain for me. ^_^;
2. Are Table 2's
Hi group,
I have a query on the understanding of the above section. I thought I fully
understood it until I used a different lab for Product Safety Compliance
testing (both accredited!).
We use a linear (basically a transformer with a PTC thermistor) class II
SELV O/P stand alone power supply
Stuart,
I would assume that the power supply providing power to the fence is the
normal utility supply (115/230 V). Therefore, the system is indeed covered
by the LVD.
This e-mail message may contain privileged or confidential information. If
you are not the intended recipient, you may not
Pierre,
The compliance criteria for abnormal operating and fault conditions are
specified in 5.3.8.1 (during the tests) and 5.3.8.2 (after the tests). These
specs do not require you to measure SELV voltages during or after abnormals
and this is why in many test reports you do not see the SELV
Ah yes, -sparking, sizzling wire fences...
About 40 yrs ago I spent a few summers visiting with an uncle and family on
his Iowa farm.
He had a small electrified pen with hogs in it.
My cousin would dare me to take a blade of grass and loop it around the wire
to see how much jolt I could take
Sorry to knock your substantially built comment, but the derating is
not based on the plug. In fact the 15 and 20 amp plugs are the same
construction with different configuration. Both can be used at full
rating. The circuit they are used in contains the limitation.
The derating on North American
Peter,
There is a summary for PCB design rules relating to EMC , (131351 bytes).
It deals with the developments, rules and guidelines leading to my thesis,
http://www.geocities.com/timfoo6143/Design_Rules.pdf
A link could be found in the main page which leads to the rest of the
thesis.
I read in !emc-pstc that Cortland Richmond 72146@compuserve.com
wrote (in 200208291324_mc3-1-dc8-8...@compuserve.com) about
'Transmission line formula?' on Thu, 29 Aug 2002:
Put two 3-foot pieces of your material at some convenient spacing. Using a
Z meter, find the quarter-wavelength
I read in !emc-pstc that Doug McKean dmck...@corp.auspex.com wrote (in
004b01c24f87$66393680$cb3e3...@corp.auspex.com) about 'Insulation
Distance Between Circuitboard Layers (Safety)' on Thu, 29 Aug 2002:
FR4 has a dielectric factor of about 4.7. That simply
means it's 4.7 times stronger than
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