Microwave tester - kicking off the breaker

Has anyone that used the microwave testing device that you can pick up from NACHI and have the circuit breaker kick off?

It kicked off immediately…

No, but did it do the same thing when you re-tested the microwave with a glass of water?

Which testing device did that, and for how long did you microwave it?

I use the Tribble, for about 20-30 seconds, and its hot, but no longer, as I don’t wan’t to cook the darn thing…I need to use it again in the future!

And I use the Plexiglas thingy, but instructions say no longer than 20 seconds,
or the bulb burns out, and sparks will fly…

That little tester is not going to cause that.

It was a problem with the microwave, not the tester. A microwave oven will “cook” just about anything you place within it.

I agree. It sounds like the microwave has some kind of short in it. If your not quite sure try the water test that Mark suggested, but it needs to be called out.

There are many possibilities, bad breaker, receptacle, improper sized conductor or breaker, loose connection at breaker or receptacle, extention cord, too many appliances on the circuit. If possible, try the Microwave on another circuit before you report it as bad. The Microwave has it’s own overload device inside, but do not attempt to service the appliance, the Magnetron puts out about 5,000 volts DC, it is deadly, DC will kill you very fast.

This would be the first thing I would investigate. A 1200 watt microwave and a 15 amp fridge defrost cycle going simultaneously on the same circuit would trip the breaker, no matter what you attempt to nuke in it.

Thanks for all the input.

This was not during the inspection. I had received some of these to pass out to the Home Inspector students where I instruct. One of the students came back with the information the next day that this happened.

I gave him mine to try and see if it happens with the one I have.

I do not have any feedback yet to see if this happens again.

I have the one that was used when the incident happened. It will not be reused. No reason to take a chance.

Probably a coincidence that the breaker kicked at the time he used the tester.