Ted, thank you for your response. I do not claim to be an expert, but I cannot accept that creepage has anything to to with the current flowing in a circuit. Surely it is the voltage across the material and the CTI of that material which determines the likelihood of tracking across the material to take place.
As for your car battery melting story, cars must be wired differently in the US than in the UK, because I have connected negative to negative and positive to positive on many occaisions, and never had anything anymore exciting happen than the second car starts. Best regards, David Sproul. -----Original Message----- From: [email protected] [mailto:[email protected]]On Behalf Of Ted Rook Sent: 09 October 2002 15:28 To: < Subject: David Sproul...UL creepage limits ;~) This is because when you double the voltage the power is proportional to a quarter of the current squared. In America the 120V power is at lower voltage but the current is twice as much and so the creepage is twice as well. Very high voltage circuits hardly creep at all whereas low voltages creep the most. That is why you should never join the two negative terminals when you jump start a car, the car battery charging circuits have so much creepage they can melt the battery. I though everybody knew that........... ------------------------------------------- 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] All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on "browse" and then "emc-pstc mailing list" ------------------------------------------- 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] All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on "browse" and then "emc-pstc mailing list"
