Microwave ovens are notorious for causing power outages by tripping circuit breakers.
Circuit breakers are designed to trip and disconnect the appliance from the electricity supply when a certain threshold of current is reached for which the breaker is rated. This action is meant to protect the appliance from the current getting dangerously high and damaging it. However, if it happens frequently or soon after turning the microwave on, you will need to find and fix the cause of the problem.
This article will review my recommended ways to fix a microwave tripping circuit breaker.
When a circuit breaker trips while using a microwave, remove any additional devices or appliances on the same circuit as the microwave, if any, before switching the breaker back on. Also, inspect and replace any faulty cords or sockets on it, or test the circuit breaker at the main panel. If none of this is the problem, check the microwave oven, as it may need to be repaired.
Fixing the Problem of a Microwave Tripping a Breaker
In a recent article, I looked at the possible main causes of why a microwave might trip a circuit breaker. See ‘Why Does a Microwave Trip a Circuit Breaker?’
The reasons were divided by location into problems at the main panel, the circuit, and the microwave oven itself. They all cause a high current to arise, which trips the breaker. Once the cause of the problem is located, you can then fix it by calling a technician or taking the appliance to a repair center.
I will briefly cover ways to fix the problem according to where it is happening, know what signs to look for, and advise you on what you can do to fix it.
A Problem at the Main Panel
A common cause of breaker tripping is the breaker itself, especially if it is old or there has recently been a high power surge or disruptive storm.
If you suspect the breaker to be faulty, you can test it using a multimeter. If it is necessary to replace it, you will also need a screwdriver and a new breaker. The required breaker is normally 20 amps.
Method to Test the Breaker: Set the multimeter to AC, switch the breaker to the on position, and place the neutral (black) probe on the neutral wire connection and the live (red) probe on the screw holding the wire in the breaker.
What to Check: The reading should be more or less the voltage of your electricity supply. If it is, the breaker is working, but if the voltage is zero or very low, it needs replacing.
A Problem in the Circuit
Another common cause of tripping is an overloaded or damaged circuit.
The circuit may be overloaded if you have another device or appliance on it, and it is used simultaneously while operating the microwave. You will have to remove all other devices and appliances and, if necessary, arrange a dedicated circuit for sole use by the microwave oven.
If you notice any damage to the power cord anywhere along the circuit or a sign of the socket melting, then, needless to say, you must stop using the circuit and replace it before using the microwave again.
A Problem with the Microwave Oven Itself
There are several indications that a certain part of the microwave oven is faulty for causing the short circuit or high current, in which case you will need to have it repaired or replaced.
For example, the timer might be jammed, preventing the microwave from shutting off automatically at a critically high temperature, or the door safety latch switch may be broken. A short circuit in the turntable motor can also cause a high current, which must be dried thoroughly. Other parts that can become faulty are the magnetron or capacitor.
The next question-answer section shows you the signs that might indicate a certain part is faulty. Whichever part it is, the only solution is to repair it if possible or replace it.
Things to Check and Fix
Here are some questions you can ask yourself and things to check and do to fix the problem before switching the circuit breaker back on.
They are roughly in an order you might want to check things. All of them are possible causes of high currents passing through and tripping the breaker.
First Things to Check on the Spot
Are you using anything else on the same circuit as the microwave?
If so, remove it, don’t do it again, and consider arranging a dedicated circuit for the microwave oven.
Do you see any sign of damage on the socket or cord?
If you do, don’t switch the breaker or microwave on again until you have replaced the socket or cord.
Is there a problem with the timer or door safety latch?
The timer or door safety latch might cause the tripping, but it should be fixed anyway for safety reasons if there is a problem. Have this part fixed or replaced.
Do you notice a problem with the circuit breaker?
Test the circuit breaker in case it is faulty. Suspect it as the cause, especially if it is old or there was a recent power surge or storm.
Other Things to Check
Does the microwave emit an abnormal noise when turned on?
There might be a problem with the capacitor or other components. Has a technician checked the microwave?
Are you cooking frozen food or defrosting, or have you done that recently?
The turntable motor may be short-circuited. Turn the microwave off and dry the turntable thoroughly. If you cannot reach the motor, have a technician check it.
Is the food not heating properly?
There might be a problem with the magnetron. Have a technician check the microwave.
Wrapping Up
We showed several ways of fixing a microwave tripping a circuit breaker once the cause of the problem is identified.
One common reason is using additional devices or appliances on the same circuit, which should be removed before switching the breaker back on. If necessary, arrange a dedicated circuit for the microwave. Look also for any damage to the cord and power outlet, which must be fixed if that is the case. If the problem is located in the circuit breaker, it will need to be tested and, if necessary, replaced.
Otherwise, some microwave parts, if faulty, can also cause a surge in current. In this case, identify the part using the questionnaire above, and have that part either repaired or replaced.
Video Reference
Bill Newberry Second