Dear John,
Varistors to Ground (earth) is a very old fashioned way for
designing equipment to withstand transient voltages. A better and
more sophisticated way is to use some better engineering
principles; for example larger clearances/creepages (approx 6 mm)
and good design of the power
equipment type A, or is the spark-gap
/ fuse requirement in effect for pluggable equipment type B as well?
2) Will Denmark, UK, and Sweden accept varistors to ground if the circuit
contains a spark-gap and two fuses?
If this Decision means DK, UK, SE will simply not accept varistors to
ground
equipment type A, or is the spark-gap
/ fuse requirement in effect for pluggable equipment type B as well?
2) Will Denmark, UK, and Sweden accept varistors to ground if the circuit
contains a spark-gap and two fuses?
If this Decision means DK, UK, SE will simply not accept varistors to
ground
This information is very timely since I am currently working on a project
that requires varistors to ground. The varistors are not approved. How
does one size the spark gap firing voltage and the fuse value? I am
concerned with the fuse opening when the equipment sees a transient.
Also
Hello;
I appreciate the discussions and information gained. Can any point me to where
on the Web I can get copies of CENELEC Decisions such the referenced CENELEC
Decision (dated 6/98)?
Thanks,
Ray Hulinsky
RCIC - http://www.rcic.com
Regulatory Compliance Information Center
-
To: emc-p...@majordomo.ieee.org
cc:
Subject: RE: Varistors to ground
Volker, thank you for this useful information. You indicated that
the decisions are to be followed by all of the test houses, yet many of the
decisions appear to be accepted in only some countries. If all of the test
houses
Stuttgart, Germany
owner-emc-p...@majordomo.ieee.org on 16.12.98 02:55:01
Please respond to jeich...@statpower.com
To: emc-p...@majordomo.ieee.org
cc:
Subject: RE: Varistors to ground
Volker: Thanks for the explanation.
I am left with 2 questions:
1. You wrote The new decision is not part
been written by people aware of the OSM/EE
decisions, who consciously did not include the decisions in the new
edition, then do they mean that varistors to ground are acceptable and
not subject to the requirements in the 2 decisions you quoted?
2. It isn't clear whether the recent decision allows
Volker, thank you for this useful information. You indicated that
the decisions are to be followed by all of the test houses, yet many of the
decisions appear to be accepted in only some countries. If all of the test
houses are expected to follow the decision, why are country exceptions
---
owner-emc-p...@majordomo.ieee.org on 15.12.98 02:11:00
Please respond to jeich...@statpower.com
To: j...@bighorn.dr.lucent.com
cc: emc-p...@majordomo.ieee.org
Subject: RE: Varistors to ground
John: Sorry I can't help, but I am interested in what replies you get.
I also wonder what force
...@bighorn.dr.lucent.com]
Sent: Monday, December 14, 1998 9:07 AM
To: 'emc-p...@ieee.org'
Subject: Varistors to ground
All:
I have received a copy of a CENELEC Decision (dated 6/98) regarding
the use
of varistors between mains conductors and ground. This particular
Decision
is written in a rather
requirement in effect for pluggable equipment type B as well?
2) Will Denmark, UK, and Sweden accept varistors to ground if the circuit
contains a spark-gap and two fuses?
3) The installation instructions for our PABX systems include the
requirement for a permanently connected ground wire between
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