OOPS! In my recent posting, I proved that human memory is a very fallible thing. I stated that in the failed GFCI outlet I examined, the sense coil measured current in the GROUND conductor. Thankfully, Jim Eichner pointed out that such a circuit would not fulfill the most important need for a GFCI. This forced me to sweep away some of the cobwebs and peer more closely into the gray matter filing cabinet. I now remember that the HOT and NEUTRAL leads both passed through the sense coil. Otherwise, the device was exactly as described. My apologies for posting incorrect information, and thanks to Jim for getting me back on track.
Scott Lacey *********************************************************** Jim Eichner responded: "I was under the impression that the sense coil does NOT sense current in the ground wire, but rather it senses any imbalance between the currents on the Line and Neutral conductors. The difference is crucial, in that only the latter can detect fault current going directly to ground (e.g. by a water pipe) rather than back to the receptacle ground." *********************************************************** --------- This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
