This question appeared on the Mike Holt forum and they gave him a lot of advice to "call an electrician": "I have (had!) an above the stove microwave which plugged in to a receptacle above it in a cabinet. It's been there for over 3 years and operated without any problems. A few weeks ago the microwave stopped working. I replaced the fuse in the microwave and the electronics functioned properly but when it was actually ran, it completely stopped working. I purchased a new microwave, mounted it and the second I plugged it in, there was a large popping sound and a large spark traveling down the backside of the microwave. Needless to say it spooked me a bit." I would like to expose this question to a wider audience in the hope of finding a cause for this catastrophe. The only thing I can think of is perhaps a 240 volt receptacle but I somehow doubt it. Has anyone had a similar experience? ~Peter
Your typical microwave comes with a NEMA 5-15 plug, so it shouldn't plug into a NEMA 6-15/20 outlet... I'd start with a voltage reading from the outlet under load... Something smells of open neutral/multiwire circuit.
Tony, if it scares you so much then by all means don't use the method, for those of us who do use it and never have problems with it, we will continue to do so. Your bad experiences can probably be attributed more to sorry workmanship of the installer(s)than to the wiring method itself.
If it's so terribly bad you should lobby to have all residential services redone with individual grounded conductors for each ungrounded conductor worldwide, after all they are MWC's.
[This message has been edited by Roger (edited 01-03-2007).]
"Your bad experiences can probably be attributed more to sorry workmanship of the installer(s)than to the wiring method itself."
I am no fan of multi wire circuits, being used just for the purpose of saving a few bucks, but that does not make them bad, or dangerous to install, they have their place, and i would use them without worry, the problems usually arise, when they are installed by someone that does not understand them.