As long as there is no other path to ground, a line to line test would be all thats required, but keep in mind, if you have other I/O, telecom, control lines, or anything else coming out of that plastic box, you then have a potential path back to ground, and in fact, will likely have REAL ground connections. For example, many television sets have two wire power plugs, are in plastic cases, but if you have cable tv, the odds are that coax cable is grounded. Same thing applies if there is a telecom line involved -- very likely one of the telecom lines is ground. ......
Mike Hopkins [email protected] > -----Original Message----- > From: Jim Hulbert [SMTP:[email protected]] > Sent: Wednesday, March 01, 2000 10:32 AM > To: [email protected] > Subject: Surge Testing per EN 55024/EN61000-4-5 > > > > > Colleagues, > > EN 55024 calls for surge pulses to be applied line-to-line and > line-to-earth on > the AC mains port and line-to-ground on signal and telecommunications > ports that > connect directly to outdoor cables. However, if my EUT is encased in > plastic > covers and has no direct earth ground connection (class 2 power supply), > is the > line-to-line test on the AC mains the only surge test that I need to > apply? It > seems to me that performing a line-to-earth test on either the AC mains > port or > on signal/telecommunications ports is not warranted since the basic > standard EN > 61000-4-5 does not specify placing the EUT over a reference ground plane. > With > no reference ground plane and no direct ground connection how can a test > be > applied with respect to ground? > > Jim Hulbert > Pitney Bowes > > > > --------- > This message is from the IEEE EMC Society Product Safety > Technical Committee emc-pstc discussion list. > > To cancel your subscription, send mail to: > [email protected] > with the single line: > unsubscribe emc-pstc > > For help, send mail to the list adminstrators: > Jim Bacher: [email protected], or > Michael Garretson: [email protected] > For policy questions, send mail to: > Richard Nute: [email protected] > ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: [email protected] Michael Garretson: [email protected] For policy questions, send mail to: Richard Nute: [email protected]
