In message 1378784340.50598.yahoomail...@web160404.mail.bf1.yahoo.com,
dated Mon, 9 Sep 2013, Bill Owsley wdows...@yahoo.com writes:
Indeed... the protection scheme that passes Safety, causes the system
to 'fail safe' which does not meet the EMC immunity requirements
Plain EMC requirements
Hello Brian,
I've employed spark gaps, like you, not because you 'have' to but because it
seemed good practice. It involved a control installation with cables strung
externally.
My advice is to use propriatory discharge tubes. They're cheap and their
performance is more predictable than
Some years ago I was working at in a wireline telecomms equipment
maker. Robust protection was the order of the day; the outside physical
plant was just *waiting* for lightning.
We protected each circuit to a level it could withstand, and worked back
to the line inputs, where (IIRC) we had
[mailto:ton...@europe.com]
Sent: Monday, September 09, 2013 4:18 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] Spark Gap PCB Layout on AC Mains
Hello Brian,
I've employed spark gaps, like you, not because you 'have' to but because it
seemed good practice. It involved a control installation
Yet another example that transistors and IC’s were invented to protect fuses
and surge protectors.
Gary
From: Kunde, Brian [mailto:brian_ku...@lecotc.com]
Sent: Monday, September 09, 2013 8:31 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] Spark Gap PCB Layout on AC Mains
What
Hi Brian,
Standard IEC 60950-1 only allows use of MOV or combination MOV + GDT in
primary circuit. No other surge protectors are allowed.
As you mentioned, manufacturers are mostly using T protection (2 MOVs and one
GDT).
Best regards,
Bostjan
On 9. sep. 2013, at 18:00, Cortland Richmond
In message
64D32EE8B9CBDD44963ACB076A5F6ABB0266533F@Mailbox-Tech.lecotech.local,
dated Mon, 9 Sep 2013, Kunde, Brian brian_ku...@lecotc.com writes:
What are the safety considerations using gas tubes on the AC mains? Do
you have to fuse them or are they not likely to fail shorted?
Not
to all.
The Other Brian
From: Anthony Thomson [mailto:ton...@europe.com]
Sent: Monday, September 09, 2013 4:18 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] Spark Gap PCB Layout on AC Mains
Hello Brian,
I've employed spark gaps, like you, not because you 'have
of
induction
will reduce the surge current substantially.
Regards,
Ing. Gert Gremmen, BSc
Van: Joe Randolph
[mailto:j...@randolph-telecom.com]
Verzonden: Friday, September 06, 2013 11:32 PM
Aan: EMC-PSTC@LISTSERV.IEEE.ORG
Onderwerp: Re: [PSES] Spark Gap PCB Layout on AC Mains
Hi Gert:
Do you know
is fine for the Safety guys.
From: McInturff, Gary gary.mcintu...@esterline.com
To: EMC-PSTC@LISTSERV.IEEE.ORG
Sent: Monday, September 9, 2013 11:42 AM
Subject: Re: [PSES] Spark Gap PCB Layout on AC Mains
Yet another example that transistors and IC’s were
are trying to protect are
buy/sell components where we do not control spacings.
Any comments?
Thanks to all.
The Other Brian
From: Anthony Thomson
[mailto:ton...@europe.com]
Sent: Monday, September 09, 2013 4:18 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] Spark Gap PCB Layout on AC Mains
Onderwerp: Re: [PSES] Spark Gap PCB Layout on AC Mains
Hi Gert:
Do you know of a source for a small, inexpensive gas tube with a rated
breakdown voltage in the range of 6 KV to 10 KV? I don't, but I'd like to know
of a suitable source.
As I noted, conventional gas tubes are typically rated
In message FCA549BE3ECF9D4CB8CB8576837EA48920A1A4@ZEUS.cetest.local,
dated Sat, 7 Sep 2013, ce-test, qualified testing bv - Gert Gremmen
g.grem...@cetest.nl writes:
Anyway, the primary circuit always need to be build for high surge
currents,
and one should always insert induction to limit
bericht-
Van: John Woodgate [mailto:j...@jmwa.demon.co.uk]
Verzonden: Saturday, September 07, 2013 11:35 AM
Aan: EMC-PSTC@LISTSERV.IEEE.ORG
Onderwerp: Re: [PSES] Spark Gap PCB Layout on AC Mains
In message FCA549BE3ECF9D4CB8CB8576837EA48920A1A4@ZEUS.cetest.local,
dated Sat, 7 Sep 2013, ce-test
I often see spark gaps on the mains side of AC-DC power supplies PCBs. I
consider it a best practice.
Gary Tornquist
Director of Product Safety
Microsoft Corp
From: Kunde, Brian [mailto:brian_ku...@lecotc.com]
Sent: Friday, September 6, 2013 8:56 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject:
Brian,
I am personally opposed to such an idea. The first time I saw this was circa
1982 on an electronic security system; designed to tie into the public
telephone network. The manufacturer wanted additional protection above the
outdoor surge protector. The design involved two parallel
Hi Doug:
I think we are in agreement about some of the pitfalls of spark gaps that
are simply added in the copper layout.
Regarding spark gap components, the devices you cite (also
known as gas tubes) typically fire at just a few hundred volts.
Adding these to enhance the surge tolerance of an
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] Spark Gap PCB Layout on AC Mains
Brian,
I am personally opposed to such an idea. The first time I saw this was circa
1982 on an electronic security system; designed to tie into the public
telephone network. The manufacturer wanted additional
, Brian; EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] Spark Gap PCB Layout on AC Mains
Brian,
I am personally opposed to such an idea. The first time I saw this was circa
1982 on an electronic security system; designed to tie into the public
telephone network. The manufacturer wanted additional
In message
64D32EE8B9CBDD44963ACB076A5F6ABB02664E67@Mailbox-Tech.lecotech.local,
dated Fri, 6 Sep 2013, Kunde, Brian brian_ku...@lecotc.com writes:
I have seen spark-gap lay outs on PC boards on I/O connectors; usually
for ESD protection, but not on AC Mains. Is this a bad bad idea or
Murphy says it will destroy BOTH boards.
Ed Price
WB6WSN
Chula Vista, CA USA
From: Kunde, Brian [mailto:brian_ku...@lecotc.com]
Sent: Friday, September 06, 2013 10:15 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] Spark Gap PCB Layout on AC Mains
The thought is that a really
PCB gaps (with or without slot) are okay for low-current
discharges. For high-current discharges such as occur
on mains circuits, the current will vaporize the copper
and increase the clearance distance, and thereby increase
the breakdown voltage with each overvoltage event.
Rich
On
@LISTSERV.IEEE.ORG
Onderwerp: Re: [PSES] Spark Gap PCB Layout on AC Mains
Hi Doug:
You mention that there are companies that make air gaps. Are these devices
anything like what I described?
What I have in mind is an inexpensive component about the same physical size
and cost as a gas tube
From: Joe RandolphSent: Friday, September 6, 2013 1:05 PMTo: Doug Powell; EMC-PSTC@LISTSERV.IEEE.ORGSubject: Re: [PSES] Spark Gap PCB Layout on AC Mains
Hi Doug:
You mention
doug...@gmail.com
http://www.linkedin.com/in/dougp01
From: Joe Randolph
Sent: Friday, September 06, 2013 11:34 AM
To: Doug Powell ; EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] Spark Gap PCB Layout on AC Mains
Hi Doug:
I think we are in agreement about some of the pitfalls of spark gaps
E Powell
doug...@gmail.com
http://www.linkedin.com/in/dougp01
From: Joe Randolph
Sent: Friday, September 06, 2013 11:34 AM
To: Doug Powell ; EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] Spark Gap PCB Layout on AC Mains
Hi Doug:
I think we are in agreement about some of the pitfalls of spark
I'm not a power engineer, but I suspect you'll need something more than
pointed bus bars. A quick search comes up with this:
www.erico.com/public/library/fep/Surge/LT19915.pdf?
Good luck!
Cortland Richmond
On 9/6/2013 1156, Kunde, Brian wrote:
Our engineers are working on an AC Mains
In message F5B74858AAFC4C929D1E6F81869E1EA0@ComputerNo11, dated Fri, 6
Sep 2013, Doug Powell doug...@gmail.com writes:
Best to simply use a glass or ceramic spark gaps which are inorganic
and cannot produce carbon when arced
You are right: using PCB tracks is to invite tracking! A slot in
Hi Brian:
I think it is a good idea to increase the spacings if you have room
available. The statistical relationship between peak surge voltage
and probability of occurrence strongly favors larger spacings.
Doubling the spacings may reduce the probability of breakdown by a factor
of ten.
to reduce the current. That fits nice with your observations on
high breakdown voltages.
Gert Gremmen
Van: Joe Randolph
[mailto:j...@randolph-telecom.com]
Verzonden: vrijdag 6 september 2013 21:06
Aan: EMC-PSTC@LISTSERV.IEEE.ORG
Onderwerp: Re: [PSES] Spark Gap PCB Layout on AC Mains
Hi Doug:
You
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