To whichever Brian posted the original message, :-) To focus this discussion a bit, UL has a 1000A test (you read correctly) to evaluate intended earthing PWB traces. Actually, the current source is capable of that, but there is a 30A circuit breaker in series along with bus bars and 12AWG wire. The objective of the test is to see if the trace's resistance was less than 0.1ohm before and after the test along with noting the change in resistance. However, for specific details of this test, please consult your UL engineer.
This brought to my mind a tee shirt I encountered recently "A single test is worth more than the opinions of a thousand experts". This saying stuck with me. Anyway, IHTH. Best regards, Ron Pickard [email protected] From: [email protected] [mailto:[email protected]] On Behalf Of Kunde, Brian Sent: Monday, February 05, 2007 7:49 AM To: emc-pstc Subject: Protective Earth through PCB traces Members, There was an article in one of the many trade magazines we get a few years back about running PE or Safety Earth ground traces on a PCB and how they needed to be designed so not to get damaged during a short or overcurrent situation. I can't find this article so if anyone help me out I appreciated it. We are using a "Distribution Card" to power AC sub assemblies in our product. So we want the PE traces in this distribution card to handle the fault current without damage. The sub assemblies have a fault current in the 5 to 10 amp range depending on the assembly. Our CAD guys just want a current value for the PE so they can plug into their computer and it will make the trace width wide enough to handle the current. So is X2 the fault current enough? I thought the article I mentioned above recommended X3 or X4. Appreciate any recommendations. The Other Brian. - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to [email protected] Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas [email protected] Mike Cantwell [email protected] For policy questions, send mail to: Jim Bacher: [email protected] David Heald: [email protected] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to [email protected] Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas [email protected] Mike Cantwell [email protected] For policy questions, send mail to: Jim Bacher: [email protected] David Heald: [email protected] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc ______________________________________________________________________ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email ______________________________________________________________________
