208v and voltage, microwave oven

Definitely 208.

-- Tom H

Generally, by historic "treaty," 208V appliances are intended to operate OK on about 191-218V... er, not catch fire anyway.

?s falke

"buildmorel> I hooked up a 208/240v commercial microwave over to my system, I made

| I hooked up a 208/240v commercial microwave over to my system, I made | the outlet today. The microwave has a voltage selector on it. When I | measure it, it shows 209-211v constantly going up and down on a volt | metter. Should I be running my microwave on 208V mode, or 240V mode?

I'd go with the 208 volt selection. If you have 3-phase power coming into the building, it's probably 208Y/120 and your outlet is wired for line-to-line voltage. Measure the line to neutral voltage and see if it is about 122. The ratio will be 1.732:1 if three phase.

Unlike some more agile devices like switching power supplies, which can be made to work through quite a wide voltage range (at the expense of having high harmonics), some things like lights and motors have more of a problem with wide voltage swings. I've seen 240 volt motors burn out on 208 volts.