Microwave Power fluctuations

Old 11-22-00, 05:01 PM
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Just installed new built in Microwave, old one was having power fluctuations, lights dimming, then it quit. New one installed is doing the same thing? I changed the recepticle, and used a volt meter to check it and I'm showing 119.8 volts. It is plugged into it's own line with a 15 amp breaker. Help... I need the microwave for Thanksgiving dinner !
Old 11-22-00, 05:13 PM
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When you say it's plugged into its own line, I'm assuming you mean a dedicated circuit? A cable runs directly from the circuit breaker to this one outlet, and does not even so much as go to another outlet or switch before or after this outlet?

Just because it reads 120 volts under no load doesn't mean it has 120 volts under load. Conduct this test: hook your voltmeter up to the outlet, turn the power back on, then plug in the microwave. See how much the voltage drops when the microwave is turned on.

Check for poor connections. First recheck the outlet you changed. Do not use the push-in connectors on the back. Securely wrap the wires around the screws clockwise and tighten well. Then check the connections on every other outlet or switch on this circuit (if any) in the same way. Finally, check the connections at the circuit breaker panel (WARNING: BE SURE YOU KNOW WHAT YOU'RE DOING IF YOU OPEN THIS PANEL -- EXTREME HAZARD!).

Now, redo the test you started with and see if you made a difference.

Good luck.
Old 11-22-00, 05:41 PM
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John Nelson is right. I would do what he suggested by testing the voltage while under load. If you find the power does not on the voltage tester noticably then you might try checking the following; You may have a voltage problem but it sounds like you may have a microwave mode problem. Microwaves have a medium and low setting on cooking that will start high then switch to low power within the control. Also microwaves usually have a defrost mode that lowers the voltage.

If all else fails plug in a temporary extension cord to another power source and test the microwave. If it still seems with low voltage it is probably in your microwave programming user designed. If the microwave works fine on another circuit then go back to what John suggested again.

Good Luck

Old 11-23-00, 08:26 AM
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I know this may sound dumb,but after doing the above suggestions go to an electric suppl y I doubt that home depot will have it and buy a renasonce breaker { that is not brand name that is what it is called }.This is a new type made breaker for microwaves am not familiar with them my self. These are breakers made for the newer microwaves,just found this out from an AC REPAIRMAN AS HE WAS HAVING PROBLEMS WITH HIS NEW MICRO UNTIL HE PURCHASED THIS BREAKER AND INSTALLED IT SORRY ABOUT THE CAPS did not realize they were on

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