Exactly! There is lots of data and tables available on the web for steady state current; but I haven't found any sources that would give the (I^2)(t) values for wires or PCB traces. Such tables would take a great deal of mystery out of this subject. Right now, the best guess is to go by steady state current rating; but there must be faults in this. A PCB trace that can handle 10 Amps of steady state current has a totally different geometry than a wire that can handle 10 Amps of steady state current. This would make heat dissipation different; and I would assume that it would make the fusing characteristics (I^2)(t) slightly different as well.
Chris Maxwell | Design Engineer - Optical Division email [email protected] | dir +1 315 266 5128 | fax +1 315 797 8024 NetTest | 6 Rhoads Drive, Utica, NY 13502 | USA web www.nettest.com | tel +1 315 797 4449 | > -----Original Message----- > From: drcuthbert [SMTP:[email protected]] > Sent: Monday, February 03, 2003 7:50 PM > To: 'John Woodgate'; [email protected] > Subject: RE: EN60950 protective conductor test (was Re: Circuit Breaker Tripping Dring Fault Tests) > > > What is needed is the I squared t rating of the breaker. Then the (I^2)(t) > rating of the PCB. Then you know if the PCB can take it. > > Dave Cuthbert > > This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: [email protected] Dave Heald: [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
