{Qouted by Scott35}
"One other item - which goes in conjunction with "Service Equipment" is GFPE Protected Main Disconnects.
Ground faulting on the Load side of 480Y/277V 3 Phase 4 Wire Solidly Grounded Wye Systems of 1,000 Amps and larger, will result in tripping the _MAIN SERVICE DISCONNECT_
When this happens, it brings down the entire Building on that service.
Indications of tripping a GFPE main are:
* Only Emergency Lighting is on,
* Kwh Meter at the Main Service is not spinning / recording any consumption,
* Pissed-Off Tenants wandering around, looking for someone to point fingers at,
* A distant sound of the Back-Up Generator starting. ""
that is the famous situation i ran into few time sure, sure , the tenents will cuss in very colourfull langunge some time it will show up in forgen langaune as well.
the last time it happend to me was a week ago one of the ground wire bump with netural wire that will trip the GFI system and i can heard the transfer switch kicked over to genny power i say [cussing in French ] oh well i have to reset the big 2500 amp 480 switch [ i have a chicken switch to do this for me ] to prevent flash over on me if something go wrong
Merci , Marc
P.S. if you plan to shut the main building power in large commercal area ya better plan that ahead of the time [ some will say heck no to this ]
Last edited by frenchelectrican; 04/02/07 01:44 AM. Reason: clean up some words a little
