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btuinstra · 05-15-2013, 09:09 PM

I have a microwave/convection oven that continually cycles when in the motorhome. When I pull it out and plug into my home power the microwave works correctly. Any ideas on what may cause this.

wvabeer · 05-16-2013, 05:06 AM

Have you tried another receptical to see if where you had it plugged in normaly could be bad.

92landyacht · 05-16-2013, 06:42 AM

Is this happening when you run the generator or using shore power or both? Likely a low voltage condition. I'd verify the voltage at the receptacle while the microwave oven is running.

GeocamperAS · 05-16-2013, 06:46 AM

What do you mean by "continually cycles"?
Is it running all the time It is plugged in OR is it going on and off on it own?

Because it only does it in your MH I would think it is the wiring in the MH.

The circuit boards in appliances can do strange things if the power supply is not correct.
Two thing that come to mind are:
1. reverse polarity. That is the hot and neutral wires are on the wrong side of the outlet.
To check this you can use a cheap outlet tester that has three lights on it. When plugged in the lights that light up tell you if it's correct or not. OR if you have a voltmeter, between the short slot (hot) and the long slot (neutral) you should get about 120 volts. Then between the short slot (hot) and the round hole (ground) you should get about 120 volts. Then between the long slot (neutral) and the round hole (ground) you should get nothing. If the last two are both nothing the outlet is not grounded. If the last two are reversed then it is reverse polarity. Appliances with circuit boards need to have the proper polarity and grounding.
2: some type of electrical interference. Here's a very simple explanation. A circuit board from one appliance that is on the same power feed as another (like the refrigerator and the microwave oven) could cause the circuit board in the microwave to do strange things like turn on all by itself. I've seen a light dimmer in the dinning room cause the range in the kitchen to go on all by it self.

Protagonist · 05-16-2013, 09:01 AM

Quote:

Originally Posted by tiger

The circuit boards in appliances can do strange things if the power supply is not correct.
Two thing that come to mind are:
1. reverse polarity.
2: some type of electrical interference.

Another possibility, if your power source is modified sine wave rather than pure sine wave, that can cause some electronics to have problems. Are you perchance operating your microwave off your converter?

btuinstra · 05-17-2013, 08:28 PM

How would I verify the voltage when the microwave is running?

btuinstra · 05-17-2013, 08:31 PM

What I mean by cycling is in the display it cycles through the numbers 1,2,3,4 continuosly and beeps with each number change

92landyacht · 05-18-2013, 06:35 AM

Quote:

Originally Posted by btuinstra

How would I verify the voltage when the microwave is running?

Normally you would use a digital volt meter and probe the same outlet that the microwave is running off of by inserting the meter probes into the socket between the hot and common. If it's not an outlet but a hard wired connection then you would remove the wire nuts and probe the wires directly. Black wire is hot and white wire is common.

I do have to add to this one point. If you have to ask this question, then you may want to find someone more electrically savvy to do the check for you. If done wrong you can hurt yourself.