Odd issue with microwave

[flyng_fool]

Had a weird surge about a week ago and microwave stopped working. Called the repair guys it and they said it wasn't the microwave but the outlet. Plugged the micro into another outlet and it works just fine. So I changed the outlet with a high grade one, not a builder grade cheapie. Micro works fine for a few seconds but when you hear the microwave gun kick on, the microwave stops working. Pulled the micro back out and put a multimeter on the outlet and it reads 120V AC steady. It seems like when a load is put on is put in the circuit it isn't able to put out enough power and shuts the microwave down. The microwave is on its own 20A circuit. Could it be a bad circuit breaker?

 

[Warrenator]

Might be a bad breaker, easy to swap out breakers in your box to see if the problem follows the breaker or stays with the outlet. If not the breaker look for a bad junction somewhere.

 

[wyliesdiesels]

Measure the voltage WHILE the microwave is running! It might be a long run of wire from the panel and the microwave is experiencing voltage drop.

Does the breaker trip?

 

[flyng_fool]

Breaker does not trip. The run is actually relatively short. Panel is in the garage and kitchen is first room you enter from garage. I'll swap out breakers and see what happens. Thanks!

 

[1/2 Cup]

Might be a bad breaker, easy to swap out breakers in your box to see if the problem follows the breaker or stays with the outlet. If not the breaker look for a bad junction somewhere.

As above...

I would be looking for a poor termination or faulty circuit breaker some where?

 

[Milton Shaw]

Some cheap breakers will not handle the surge current that a microwave draws when it pulls load (microwave tube comes on). Buy a better breaker and also check and make sure that it does not have any backstabbed outlets in the circuit that are arcing. Do check the voltage under load.

 

[flyng_fool]

AFAIK the microwave is the only thing on the circuit so I wouldn't think there are any back stabbed outlets on it. What is the best way to check it under load?

 

[Bigshed]

I had similar problem turned out to be the main breaker. To test this move the microwave breaker down or up one slot in the panel. The main was delivering only about 90 volts on one leg and 120 volts on the other.

 

[wyliesdiesels]

AFAIK the microwave is the only thing on the circuit so I wouldn't think there are any back stabbed outlets on it. What is the best way to check it under load?

Put your DMM probes into the other receptacle that shares the outlet the microwave is plugged into. Set it to AC voltage.

 

[flyng_fool]

Thanks, I'll do that and let you know the results.

 

[flyng_fool]

Changed the CB. So far so good.

 

[wyliesdiesels]

Changed the CB. So far so good.

What brand and make of panel do u have? Say it aint a sh*tsco(Zinsco) or an FPE stab-u-in-the-back(FPE stab-lok)....

 

[flyng_fool]

Square D