Situation: 0.5 inch (13mm) diameter hole punched in
a metal chassis through which is passed a fiber-optic
connector. Once the connector has been passed thru
the hole, you're left with the small diameter cable dangling
in a gaping 1/2 inch hole. High noise environment inside
the product
Hi Andy,
Most of the ports are linking to offsite support equipment or looped back to
get link. The response seems consistent regardless of how it is linked. There
is also some tuning; broadband humps up a little higher in one spot or another
but not a real big factor. I have tried 50 ft and
I read in !emc-pstc that rlinf...@sonicwall.com wrote (in D5FCAC81D18F0
d4e8e7df3734de064f2375...@usexch3.us.sonicwall.com) about 'Ethernet
Radiated Emissions' on Wed, 9 Oct 2002:
With all cables attached and not linked there is no broadband. Reducing the
resolution shows peaks every 60 kHz.
I read in !emc-pstc that John Shinn john.sh...@sanmina-sci.com wrote
(in 008b01c26fd7$4f20da00$af8c1...@hadco.comsanmina.com) about
'Question regarding something slightly unusual ...' on Wed, 9 Oct 2002:
David, You are right. I have a mouse that has a UL recognized
mark, a GS mark, a CE
David, You are right. I have a mouse that has a UL recognized mark, a GS
mark, a CE mark,
a NOM, a VCCI, a Tic mark, and more. And it still does not work well.
John
-Original Message-
From: owner-emc-p...@majordomo.ieee.org
[mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of
While a mouse cannot function by itself, as it needs to be connected to
something, it is a complete product in the sense that it should comply with
the Safety and EMC standards and does not require any special safety related
install or usage instructions. It therefore is able to bear the GS
Having worked on Ethernet (100 MB UTP) EMC for a few years, I now find myself
lacking understanding of Ethernet communications and how this may be affecting
radiated emissions.
What is seen on the OATs is broadband noise between 50 and 150 MHz. With two
cables connected and linked, broadband
I read in !emc-pstc that richwo...@tycoint.com wrote (in 846BF526A205F8
4BA2B6045BBF7E9A6A0467583F@flbocexu05) about 'Question regarding
something slightly unusual ...' on Wed, 9 Oct 2002:
But that does not explain the marks on the mouse.
The mouse probably does not comply with the
I read in !emc-pstc that John Allen john.al...@era.co.uk wrote (in
BFE68AB0084CD311B4FB00508B014C8703CF9C54@MERCURY) about 'CE Mark vs.
e-Mark' on Wed, 9 Oct 2002:
Having discussed the subject with John Woodgate before sending this message,
I have now to correct his statement below that the
In a message dated 10/9/02 3:22:12 PM Eastern Daylight Time,
john_t...@bose.com writes:
Unless something has changed in the in the last two years, when I was
employed at TUV, this is actually not quite correct. The GS Mark is only
for finished ready to use products which do not require any
I would also like to recommend Pike Fischer for their FCC information on
CD-ROM. When there is a lot of money riding on a product - and there always is
- the few hundred dollars for a subscription should not be an issue - although
it usually is.
The GPO books are up to 18 months out of date.
Well I have a mouse with a UL listing mark a GS mark and a keyboard with a
Recognized component mark a GS mark. So you are correct in that it does not
work well.
About 10 years ago the UL office we dealt with would not list and product that
was rack mountable even though as an individual
Greg Galluccio wrote:
The GS Mark has no mechanism for delineating between components and
finished products - both can receive GS approval. Hence the TUV GS mark.
Unless something has changed in the in the last two years, when I was
employed at TUV, this is actually not quite correct.
The most likely reason I can think of is that some companies demand
either a UL or TUV mark specifically hence the dual marking. I knew of
one company that would accept a test report only from a specific
laboratory.
Both UL and TUV are NRTLs. It is also possible that TUV met some
Well that process doesn't seem to work that well either. I have a mouse and
keyboard that both have a UL Recognition mark. The mouse has a GS mark and
the keyboard has a Bauart mark. Of course, the reason the keyboard has the
Bauart mark rather than the GS mark is that it does not comply with the
Great apologies with the dyslexia here.
Yes, the input is 115-230vac range.
Regards, Doug McKean
---
This message is from the IEEE EMC Society Product Safety
Technical Committee emc-pstc discussion list.
Visit our web site at:
To make things simpler, it could be a stand alone workstation
with Recognition approval here in the States and with a GS
approval for Europe.
I don't want to mention any names but certainly there are well
known personal computer mfrs here in the states which
routinely get listings on their
Doug -
Dual listing is simple economics assuming you meant '115 V' by your '155 V':
Multiple approvals let you sell slow-moving US inventory overseas simply by
switching the linecord (if you supply multilingual I-I's). In the same
manner, slow-moving international inventory can be sold here.
Sounds interesting.
Typically, the UL recognition mark is used for components.
From UL's web site:
These are marks consumers rarely see because they are specifically
used on component parts that are part of a larger product or system.
These components may have restrictions on their performance
I read in !emc-pstc that Barker, Neil neil.bar...@e2vtechnologies.com
wrote (in 4f826f960057d4118ec3009027e2453808a51...@whl17.eev.uk) about
'CE Mark vs. e-Mark' on Wed, 9 Oct 2002:
The second draft of the Revised Guidelines from LVD, published in May 2000
following the Think Tank Meeting of 27th
Hi Doug,
I have seen this recently on another cord connected power supply, like you
use on a laptop, and I wondered about that too. I am speculating, but it
may be that the product was approved before TUV had NRTL status i North
America, thus an approval by an OSHA/SCC accredited third party was
TUV does have a mechanism, they issues the GS mark for products and the Bauart
mark for components.
Dave Clement
Motorola Inc.
Test Lab Services
Homologation Engineering
20 Cabot Blvd.
Mansfield, MA 02048
P:508-851-8259
F:508-851-8512
C:508-725-9689
mailto:dave.clem...@motorola.com
Hi Folks
Having discussed the subject with John Woodgate before sending this message,
I have now to correct his statement below that the official interpretation
is that the LVD applies only to the supply side of equipment:- It does not,
and it does apply to both the supply AND the output side.
From Doug McKean:
In 20 years, I've never seen this before but that's not saying much.
Why would a mfr get a UL recognition approval for a commercial
ITE style single phase 155-230vac computer style product but for
that same product get the TUV GS mark?
Mfr is a stateside company.
My recollection of a conversation many years ago is that it was not 0 and 1,
but rather O (circle) and | (line).
Leo Simon
-Original Message-
From: Brewster, Alan [mailto:alan.brews...@novellus.com]
Sent: Tuesday, October 08, 2002 7:40 PM
To: Rich Nute
Cc: emc-p...@majordomo.ieee.org
If I recall correctly the TWA-800 crash investigation included analysis of the
tubular fuel sensors described in another post here (8 feet long I think) and
the possibility of them becoming an ignition source should a power cross occur.
The investigation seemed to conclude that the source of
In 20 years, I've never seen this before but that's not saying much.
Why would a mfr get a UL recognition approval for a commercial
ITE style single phase 155-230vac computer style product but for
that same product get the TUV GS mark?
Mfr is a stateside company.
Product to be used in
David -
If component licenses or certificates are required to
support a CB Scheme Certificate and Test Report for a final
product, the onus of demonstrating compliance is on the
company obtaining the end-product Certificate. If the SSR
vendor does not have their own certifications that can
not a qualified expert in the field but first principals tell me you may have a
combination of problems.
When the solder process is correctly managed solder will form joints that have
extremely good electro mechanical integrity but which are vulnerable to thermal
stresses: repeated expansion
David,
I read from this that the relay is a recognized componet and that would
include a number of parts, relay's their contacts the opto couplers etc, all in
one package. The relay vendor will have to control all of the internal parts
and will have periodic follow-up service
John -
The case of internal use of elevated voltages (as in a lap
top computer screen backlight) is clearly addressed by the
interpretation.
To test the consistency of the interpretation, imagine a
product with a supply voltage below the limits in the LVD,
where the LVD would not apply to that
Seems simple enough request but for every reference I'm going to give
you someone will point out that some RBOC or other has different requirements,
and they will be quite correct. In fact AT T actually calls its documents
NEDS not NEBS.
The NEBS conference is going on this
This is because when you double the voltage the power is proportional to a
quarter of the current squared. In America the 120V power is at lower voltage
but the current is twice as much and so the creepage is twice as well.
Very high voltage circuits hardly creep at all whereas low voltages
the damn frogs, did you try jump starting them with a battery :-)
There has been a change in sensor construction and design because of accidents
that occurred in scrap yards and garage workshops due to the precise scenario
you described.
First it is quite a leap of faith to treat liquid
I read in !emc-pstc that Chris Chileshe chris.chile...@ultronics.com
wrote (in 01c26f7a.00510c40.chris.chile...@ultronics.com) about
'Testing for dry joints' on Wed, 9 Oct 2002:
The specific problem is that the joints appear to be electrically
sound to start with, meaning the units are getting
I read in !emc-pstc that Barker, Neil neil.bar...@e2vtechnologies.com
wrote (in 4f826f960057d4118ec3009027e2453808a51...@whl17.eev.uk) about
'CE Mark vs. e-Mark' on Wed, 9 Oct 2002:
My understanding is that the latest interpretation is that the LVD applies
to all input or output voltages, i.e.
I read in !emc-pstc that Richard Steele rcsteel...@hotmail.com wrote
(in oe27uhqhh2wlcvyl4maf...@hotmail.com) about 'Creepage' on Wed,
9 Oct 2002:
Whilst were on the subject of creepage, can anyone shed any light why there
are
creepage distances for Printed Wiring Material shown in Table 4
Capacitive fluid level detection is an old and well proven system. I was an
avionics maintenance technician for some years and all the aircraft I ever
worked on used this technology, to include the B-52 which has been flying
since the early 1950s. Aircraft fuel level sensors have the capacitive
Hi Jim:
I don't know of any on-line information as you describe, but Telcordia
Technologies does put on seminars like one called Understanding NEBS
Compliance. I do have an old web address for them http://www.800teachme.com
.
I would recommend buying some standards even if you are just
FYI -
I saw a question about Russian telecom approval recently, and just today I
received some information in that area. I have not explored the attached
links, or verified any of the information here, so anyone using it may want
to do some verification themselves.
Richard
Richard Payne
Dear Chris,
If I remember correctly from my days in Britain's National Coal Board,
thermal imagers and other temperature sensors were used to check cable
joints underground. Poor connections had a higher resistance, and were thus
hotter, than their neighbours. I don't know whether such a test
Chris
IPC-A-610 Rev C, covers various inspection criteria for a whole host of
solder quality related issues. Most are visual inspections of the board,
but in some cases you will need to micro section the joint in question
to be sure. But generally you can see a bad joint form the visual
Hi Group,
Probably not the appropriate forum but here goes anyway.
A colleague is finding numerous problems with subtle dry
joints (partial) between connectors and PCBs and is wondering
if there is a way - short of new procedures in process control - that
dry joints can be tested for?
The
I read in !emc-pstc that Jim Eichner jim.eich...@xantrex.com wrote (in
67C475A5ECE7D4118AEC0002B325CAB603510F93@BCMAIL1) about 'CE Mark vs.
e-Mark' on Tue, 8 Oct 2002:
By the way, the LVD is in fact
applicable, because the product in question creates 120Vac from the 12Vdc it
gets from the car.
Whilst were on the subject of creepage, can anyone shed any light why there are
creepage distances for Printed Wiring Material shown in Table 4 of IEC 664-1
1992 but these are not included in EN 60950 2000 table 2L.
Regards
Richard Steele
Hi Alex and Joe
Just to add some more information:
Be sure that the ISDN circuit is in good balance and that the ISDN IC
have good ground connection and decoupling of supply. The noise can
affect other nearby circuits. Joe's idea with the caps on ISDN have to
be checked according to
You are exactly right. I used to work on automotive fuel electrical systems
about 10 years ago. The fuel meter is a current meter, measuring current
between 1 to 3 mA (for the one I used). The meter input resistance is
greater than 4k ohms. This is the current limit for the fuel sender unit,
Thanks everyone - I have my answer. By the way, the LVD is in fact
applicable, because the product in question creates 120Vac from the 12Vdc it
gets from the car.
So the answer is that since the EMCD is not applicable where the AEMCD is
applicable, there is nothing wrong with a CE Mark and a
I'm starting up the learning curve on NEBS compliance, and am looking for
any web resources or articles that would have a management-level primer on
the requirements.
All I know is that it covers EMC, safety, and environmental, there are
different levels (1, 2, and 3?), and different potential
There was a good answer on this subject about there not being an explosive
atmosphere within a car fuel tank, but I think there may be another safety
factor. If I were designing the sensor system, the meter would be
configured as an ohmmeter/ammeter, such that there would be a very high
series
Hello Group,
We are currently working with our NRTL to acquire a CB Report/Certificate
for one of our products the use a solid state relay to switch either 120V ac
or 230V ac.
This relay has been found to meet the creepage and clearance requirements
under UL 6500 (recognized component). As we
Rich,
I remember asking this question of a senior BS safety committee officer many
years ago. His opinion was that these symbols went back to steam systems
indicating the status of the boiler output i.e. the closed valve or the open
line. He went to great pains to inform me that these were not
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