Had this prob in one of our schools yesterday, opinions welcomed:
One of our new electricians installed a multiwire ckt (3 wire/shared neutral) out of a "computer only" panel (208Y120) to run two circuits for 2 identical laminators. These machines are identical. They run on 120v, have a small motor (about 1 amp) and a heating element (about 5 amps), that's it. When he plugged them in both would run the motor but as soon as he turned on the heat, they shut down internally (popped the reset). Never tripped any breaker.
He tried: 1) Turning off one breaker so the neutral was not shared. 2) unplugging one machine. Regardless of what he did, neither machine would run. As soon as he plugged them into a recep from another panel both worked fine.
Background: The computer panel is not in the comp room, it's on the other side of a block wall. He does not know what type of xfmr is feeding the panel but I suspect it's an "el cheapo" not a K. Two wire circuits gave the same prob when run from this same comp panel. There were no reported probs on the computers during his testing time. Voltage to neutral and ground read normal.
All of us school board electricians are doing what we do best here ... drinking coffee, eating donuts and scratching our heads. Any thoughts?
[This message has been edited by Steve Miller (edited 01-20-2006).]
