Why is My Microwave Tripping the Circuit Breaker?

Jul 29, 2023, 12:11pm

The microwave is a very useful appliance in the kitchen and is found in the majority of homes. This utensil has several program times and is able to heat dishes quickly. The magnetron inside will agitate the water particles in the food and heat it up, which is why you should never let the microwave run empty at the risk of damaging it. .

Maintenance is essential for this device to function for a long time. However, it is not uncommon to see frequent breakdowns on this device, it may depend on the frequency of use. If the microwave causes the installation in your home to trip, you will need to check:

  • the power outlet
  • the electrical panel
  • the power cord
  • turntable motor
  • door security
  • the transformer
  • the magnetron
  • high voltage diode
  • the capacitor

The microwave oven is a vital kitchen appliance in the modern home, offering convenience and speed in cooking or reheating food. However, it can become a source of frustration when it frequently trips the circuit breaker, interrupting your cooking process and potentially affecting other appliances as well. Here are some of the common reasons why your microwave might be tripping the circuit breaker and what you can do about it.

Why is My Microwave Tripping the Circuit Breaker?

Overloaded Circuit

One common reason your microwave might be tripping the circuit breaker is because the circuit is overloaded. Microwaves require a significant amount of electrical power to operate. If other high-power appliances are also using the same circuit at the same time, it could exceed the circuit’s capacity, causing the breaker to trip as a safety precaution.


If possible, try to distribute your high-power appliances across multiple circuits. Avoid running your microwave at the same time as other high-wattage devices, like a toaster, refrigerator, or dishwasher if they are on the same circuit.

Faulty Microwave

If your microwave is faulty or has a wiring issue, it can cause the breaker to trip. The problem could be a faulty door switch, a failing magnetron (the component that heats the food), or a problem with the transformer. Any of these issues can cause the microwave to draw more power than it should, leading to the circuit breaker tripping.


In such cases, it’s best to consult with a professional technician who can diagnose and fix the problem. If your microwave is old and frequently causing problems, you might also consider replacing it with a new one.

Short Circuit

A short circuit in your microwave could be another reason why your breaker trips. A short circuit can happen if a “hot” wire (black or red wire) touches another hot wire or a “neutral” wire (white wire) in your appliance. This can create a path of least resistance, allowing a large amount of electricity to flow, which can overload the circuit and trip the breaker.


Fixing a short circuit is a job for a professional. If you suspect a short circuit, you should stop using your microwave immediately and contact a repair technician.

Problem with Circuit Breaker

In some cases, the problem might not be with the microwave at all. If the circuit breaker is old or faulty, it could be tripping unnecessarily.


If you’ve ruled out all other possibilities and the breaker is still tripping, you might need to replace the circuit breaker or contact a professional electrician for help.


Before any intervention in the microwave oven, the parasitic filter and capacitor must be discharged.

To discharge the noise filter: Using an insulated screwdriver (or pliers), tap

  • two plugs of the socket of your device (phase – neutral),
  • then a plug and a hole in the center (phase – earth)
  • and finally another plug and center hole (neutral-to-ground).

To discharge the capacitor

  • Loosen the fixing screws and remove the cover of the device.
  • Using insulated pliers, connect the two terminals of the capacitor to create a short circuit. There may be a spark, which means the capacitor is discharged.

Why is My Microwave Tripping the Circuit Breaker?


The motor is the only part of the microwave oven accessible from below. Remember to turn off the device before intervening.

  • Remove the baking sheet, rack and rack from the microwave oven. Turn the device over.
  • To gain access to the motor, cut off small protrusions with wire cutters to remove the plate.
  • Having gained access to the motor, unscrew the screws securing it to the device.
  • Disconnect the wires connected to the motor, following the connection order, so that you can reconnect them later in the same way.

You can perform multiple tests with a multimeter.

  • When you spin the motor yourself, voltage appears on it. This is called “generator” mode. You can check this with a multimeter: place it on the gauge of an AC voltmeter (symbol V with a wave), on a gauge of 200 volts. Using pliers, rotate the motor shaft by placing the multimeter probes on the motor terminals. You should see a value close to the value on the engine label.
  • The motor also has a resistance that can be checked from the specifications written on the motor. Using a multimeter set to 2 kΩ ohmmeter mode, measure the resistance across the motor terminals. Compare the value with that indicated on the motor.
  • If there is no resistance listed on the motor, it can be calculated: (Voltage x Voltage)/Power. These two quantities are often given: voltage in volts (V) and power in watts (W). If no value is displayed, the motor is defective.


The magnetron is a box-shaped part that emits waves. It can be found either at the top above the bowl or on one side of the microwave. If the device is properly powered by the large voltage supplied by the transformer, the problem may be coming from the magnetron.

  • Disconnect the two cables from the magnetron, noticing their position, unscrew all the screws holding the magnetron, and remove it from its place.
  • Keep an eye on the condition of the magnets inside. If they are cracked or broken, it will cause the device to malfunction.
  • Also pay attention to the condition of the antenna, which should be light in color. If it is dark and has burn marks, the magnetron is in poor condition.
  • Set the multimeter to the lowest value of the ohmmeter mode (continuity)
  • Place the multimeter probes on the magnetron terminals.
  • You should see a value close to 0, around 0.5 ohms: in this case your magnetron is in good condition.


The high voltage diode plays a very important role in your microwave oven: it allows current to flow in only one direction and reduces the risk of damage in the event of a power surge.

  • Perform a continuity test by connecting the test leads of a multimeter set to continuous mode to both ends of the diode.
  • Reverse order of multimeter probes. A diode only needs to be continuous in one direction: a diode blocks the flow of current in one direction and allows it to pass in the other. Therefore, you should only hear a beep or see a value other than 1 for one of your two trials.

Remember, while a tripping circuit breaker can be a nuisance, it is a crucial safety device that protects your home from electrical overloads and fires. If your microwave is frequently tripping the circuit breaker, it’s important to identify and fix the issue as soon as possible. Always consult a professional if you are unsure about dealing with electrical appliances and circuits.