Bob, > Actually, "ground fault" circuit breakers are designed to detect any > current > flowing from the hot that does not return on the neutral. They use a > differential sensor to do this (counterwound coils, IIRC). This causes > them > to trip when current runs thru either a fault in a device insulation > or an > external path (like you) to ground. That's how I understood them to work, and I took it that Olin does too - 'caus he's a pretty smart cookie! :-) If Olin has ever seen one, he would know that he simply has not worded his sentence correctly, as an RCCB or GFI makes no connection to the ground at all. Roman and I appear to have taken this thread on a rather bizarre tangent! Anyone would think we were still talking about LEDs! :-) Cheers, Sean -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email listserv@mitvma.mit.edu with SET PICList DIGEST in the body