The actual reason for not connecting the negative terminals directly when jumpering two cars is the risk of hydrogen explosion in the presence of a spark. Positive terminals are connected first, then the negative connections made somewhere away from the battery vents. I happened to be at a Checker Auto last year when one of their personnel blew up a customers battery (in the car) while using their system tester. Quite the bang. Fortunately, no one was hurt.
Regards, Brent DeWitt "Peter L. Tarver" <[email protected]>@majordomo.ieee.org on 10/10/2002 08:58:40 AM Please respond to "Peter L. Tarver" <[email protected]> Sent by: [email protected] To: "Ted Rook" <[email protected]>, "<" <[email protected]> cc: Subject: RE: David Sproul...UL creepage limits ;~) Jeeze, Ted. I think your carb chain is loose. > -----Original Message----- > From: [email protected] > [mailto:[email protected]]On > Behalf Of Ted Rook > Sent: Wednesday, October 09, 2002 7:28 AM > 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"
