Ok, I'll be the curmudgeon... Is this really a problem in practice? Most people I've known who worked around electrical mains etc assumed the worst at all times and it isn't all that difficult to protect against as one works. I realize one can infinitely invoke "better safe than sorry!", "an ounce of prevention...!" <OBLIGATORY FUNNY STORY> Except maybe that one guy at Harvard who came to replace what turned out to be a 100+ year old, home made, "breaker" which fed our machine room which was hidden in a narrow dark hallway winding around our machine room behind an unmarked metal, locked doorway. I had no idea it existed but we had no power so I called for help. It was just a single copper bar about the size of a small candy bar tensioned into hot clips. Probably 400A but who remembers. He removed the old one confidently enough, grabbed the new one with rubber-handled pliers and gloves and... Him: Have you ever played football? Me: Actually, yes, I have, why? Him: If something doesn't look right when I put this thing in just tackle me clear of it as hard and as fast as you can. Me: Um, ok. It all worked out fine and I wrote a memo that maybe Harvard could spring for a proper $500 breaker box? </OBLIGATORY FUNNY STORY> -- -Barry Shein Software Tool & Die | bzs@TheWorld.com | http://www.TheWorld.com Purveyors to the Trade | Voice: +1 617-STD-WRLD | 800-THE-WRLD The World: Since 1989 | A Public Information Utility | *oo*