RE: LMC With Regard To Surge Test Cable Length

2000-12-21 Thread eric . lifsey
o all for a great holliday season.
Michael Taylor - NCE
Principal EMC Engineer
Hach / American Sigma divisions
Danaher Corp.

-Original Message-
From: eric.lif...@ni.com [mailto:eric.lif...@ni.com]
Sent: Wednesday, December 20, 2000 2:37 PM
To: emc-p...@ieee.org
Subject: LMC With Regard To Surge Test Cable Length



EN 61326-1 Product Family,

Laboratory, measurement, and control equipment within the scope of EN
61326-1 does not require surge testing until reaching the definition of
Long Lines (see clause 3.6) which is NOT 10 meters, but does include lines
that can leave the building.

This is an important point.  By instructing the user to not wire the
interface outside of a building and limiting the maximum cable length,
surge testing can be dropped from your test plans.  Even better, it also
encourages the customer to seek a better solution to connecting buildings.

Copper based networks or industrial I/O busses should avoid being routed
outdoors in favor of a media converter allowing the use of a purely fibre
optic cable.  This dramatically reduces the threat of a lightning induced
RF field, plus yields other odd benefits such as elimination of ground loop
potentials.

Proponents of trying to meet the surge requirement on copper interfaces are
encouraging the use of copper wiring between buildings which, in my
opinion, is risk to both connected equipment and anybody in contact with
the equipment at the moment a surge (or direct strike) occurs.

Best Regards,
Eric Lifsey
 Compliance Manager, National Instruments
 USA 512-683-8474, Fax 512-683-8880


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RE: LMC With Regard To Surge Test Cable Length

2000-12-21 Thread Michael Taylor

Great idea - - However the whole purpose of equipment designed for -
"Electrical Equipment for Measurement, Control & Laboratory use " is to
measure & control.  This can be most difficult to do if your sensors and
control points are forced to be located in the "building".  In the case of
some of my company's products you most definitely want the process away from
the building, unless you enjoy the smell of sewer lines & treatment plants".
We, as a mater of policy, surge all lines over 3 meters in length.  We have
found by sad experience that failing to do so invites customer field
"problems" and warranty issues.  By hardening our I/O circuits we ensure
correct operation of our products even when our customers place one of our
sensors / devices next to a (several) hundred HP motor.  In my opinion,  We
should be testing to the realistic conditions our products will encounter in
the real world.  By doing so, my company has lowered customer complaints and
warranty issues to the lowest in our industry segment.  A dollar saved in
warranty is a dollar earned in profit.  The net result of this is my company
is healthy and I have a reasonable expectation of continued employment up to
retirement (only 8 more years - yeaah).
Best regards to all for a great holliday season.
Michael Taylor - NCE
Principal EMC Engineer
Hach / American Sigma divisions
Danaher Corp.

-Original Message-
From: eric.lif...@ni.com [mailto:eric.lif...@ni.com]
Sent: Wednesday, December 20, 2000 2:37 PM
To: emc-p...@ieee.org
Subject: LMC With Regard To Surge Test Cable Length



EN 61326-1 Product Family,

Laboratory, measurement, and control equipment within the scope of EN
61326-1 does not require surge testing until reaching the definition of
Long Lines (see clause 3.6) which is NOT 10 meters, but does include lines
that can leave the building.

This is an important point.  By instructing the user to not wire the
interface outside of a building and limiting the maximum cable length,
surge testing can be dropped from your test plans.  Even better, it also
encourages the customer to seek a better solution to connecting buildings.

Copper based networks or industrial I/O busses should avoid being routed
outdoors in favor of a media converter allowing the use of a purely fibre
optic cable.  This dramatically reduces the threat of a lightning induced
RF field, plus yields other odd benefits such as elimination of ground loop
potentials.

Proponents of trying to meet the surge requirement on copper interfaces are
encouraging the use of copper wiring between buildings which, in my
opinion, is risk to both connected equipment and anybody in contact with
the equipment at the moment a surge (or direct strike) occurs.

Best Regards,
Eric Lifsey
 Compliance Manager, National Instruments
 USA 512-683-8474, Fax 512-683-8880


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RE: LMC With Regard To Surge Test Cable Length

2000-12-21 Thread CE-test - Ing. Gert Gremmen - ce-marking and more...

Eric,

I get the point of your story however, taking measures
against surge on signal and telecom lines is definitely
less expensive as fiber solutions. I case of a direct hit, the coupling onto
a cable length of less then 10 meters between equipment and fiber converter
is enough to kill your equipment anyway.

Following your reasons you should definitely stop testing the mains supply
connection against surges  and consider to supply your equipment with
batteries,
as lightning discharges propagate most often by the mains.



Regards,

Gert Gremmen, (Ing)

ce-test, qualified testing

===
Web presence  http://www.cetest.nl
CE-shop http://www.cetest.nl/ce_shop.htm
/-/ Compliance testing is our core business /-/
===


>>-Original Message-
>>From: owner-emc-p...@ieee.org [mailto:owner-emc-p...@ieee.org]On Behalf
>>Of Barry Ma
>>Sent: Thursday, December 21, 2000 1:33 AM
>>To: eric.lif...@ni.com
>>Cc: emc-p...@ieee.org
>>Subject: Re: LMC With Regard To Surge Test Cable Length
>>
>>
>>
>>Eric,
>>
>>To make your nice input more informative, please allow me to add
>>what clause 3.6 reads:
>>"Long distance lines: Lines within a building which are longer
>>than 30m, or which leave the building (including lines of outdoor
>>instalations)."
>>
>>BM
>>--
>>On Wed, 20 December 2000, eric.lif...@ni.com wrote:
>>
>>> EN 61326-1 Product Family,
>>>
>>> Laboratory, measurement, and control equipment within the scope of EN
>>> 61326-1 does not require surge testing until reaching the definition of
>>> Long Lines (see clause 3.6) which is NOT 10 meters, but does
>>include lines
>>> that can leave the building.
>>
>>. [clipped by BM]
>>---
>>
>>
>>Thanks.
>>Best Regards,
>>Barry Ma
>>ANRITSUhttp://www.anritsu.com
>>Morgan Hill, CA 95037
>>
>>Find the best deals on the web at AltaVista Shopping!
>>http://www.shopping.altavista.com
>>
>>---
>>This message is from the IEEE EMC Society Product Safety
>>Technical Committee emc-pstc discussion list.
>>
>>To cancel your subscription, send mail to:
>> majord...@ieee.org
>>with the single line:
>> unsubscribe emc-pstc
>>
>>For help, send mail to the list administrators:
>> Jim Bacher:  jim_bac...@mail.monarch.com
>> Michael Garretson:pstc_ad...@garretson.org
>>
>>For policy questions, send mail to:
>> Richard Nute:   ri...@ieee.org
>>
>>
<>

Re: LMC With Regard To Surge Test Cable Length

2000-12-21 Thread Barry Ma

Eric,

To make your nice input more informative, please allow me to add what clause 
3.6 reads:
"Long distance lines: Lines within a building which are longer than 30m, or 
which leave the building (including lines of outdoor instalations)."

BM
--
On Wed, 20 December 2000, eric.lif...@ni.com wrote:
 
> EN 61326-1 Product Family,
> 
> Laboratory, measurement, and control equipment within the scope of EN
> 61326-1 does not require surge testing until reaching the definition of
> Long Lines (see clause 3.6) which is NOT 10 meters, but does include lines
> that can leave the building.

. [clipped by BM]
---


Thanks.
Best Regards,
Barry Ma
ANRITSUhttp://www.anritsu.com
Morgan Hill, CA 95037

Find the best deals on the web at AltaVista Shopping!
http://www.shopping.altavista.com

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LMC With Regard To Surge Test Cable Length

2000-12-20 Thread eric . lifsey

EN 61326-1 Product Family,

Laboratory, measurement, and control equipment within the scope of EN
61326-1 does not require surge testing until reaching the definition of
Long Lines (see clause 3.6) which is NOT 10 meters, but does include lines
that can leave the building.

This is an important point.  By instructing the user to not wire the
interface outside of a building and limiting the maximum cable length,
surge testing can be dropped from your test plans.  Even better, it also
encourages the customer to seek a better solution to connecting buildings.

Copper based networks or industrial I/O busses should avoid being routed
outdoors in favor of a media converter allowing the use of a purely fibre
optic cable.  This dramatically reduces the threat of a lightning induced
RF field, plus yields other odd benefits such as elimination of ground loop
potentials.

Proponents of trying to meet the surge requirement on copper interfaces are
encouraging the use of copper wiring between buildings which, in my
opinion, is risk to both connected equipment and anybody in contact with
the equipment at the moment a surge (or direct strike) occurs.

Best Regards,
Eric Lifsey
 Compliance Manager, National Instruments
 USA 512-683-8474, Fax 512-683-8880


---
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Technical Committee emc-pstc discussion list.

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 majord...@ieee.org
with the single line:
 unsubscribe emc-pstc

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