Microwave Tripping Circuit Breaker

If your microwave keeps tripping the circuit breaker, the problem could be caused by a faulty high-voltage component, damaged power cord, failing control board, or an overloaded electrical circuit. Before replacing any parts, inspect the most common causes listed below.

Safety Notice: If your microwave repeatedly trips the circuit breaker, unplug it immediately. Do not continue resetting the breaker and operating the appliance, as this could indicate a serious electrical problem. Microwaves contain high-voltage components that can retain a dangerous electrical charge even after being disconnected from power.

Possible Causes

  • Overloaded electrical circuit
  • Faulty high-voltage capacitor
  • Failed high-voltage transformer
  • Defective high-voltage diode
  • Damaged power cord
  • Failed electronic control board
  • Shorted wiring
  • Defective magnetron

1. Overloaded Electrical Circuit

Most Common Solution

Microwaves require a significant amount of electrical power. If multiple high-power appliances are connected to the same circuit, the circuit breaker may trip during operation.

What to do:

  • Plug the microwave into a dedicated outlet if possible.
  • Avoid operating other high-power appliances on the same circuit.
  • Reset the circuit breaker and test the microwave again.

2. High-Voltage Capacitor

A shorted high-voltage capacitor can draw excessive current and immediately trip the circuit breaker.

What to do:

  • Disconnect power to the microwave.
  • Have the capacitor safely discharged before testing.
  • Test the capacitor using the proper equipment.
  • Replace it if it is defective.

3. High-Voltage Transformer

A failing high-voltage transformer can develop an internal short, causing the microwave to trip the breaker as soon as it begins heating.

What to do:

  • Inspect the transformer for signs of overheating or burnt insulation.
  • Test the transformer if appropriate equipment is available.
  • Replace the transformer if it has failed.

4. High-Voltage Diode

A shorted high-voltage diode can overload the electrical system and trip the breaker during operation.

What to do:

  • Disconnect power to the microwave.
  • Test the diode using the appropriate test equipment.
  • Replace the diode if it is defective.

5. Power Cord

A damaged power cord or plug can create a short circuit that trips the breaker.

What to do:

  • Inspect the power cord for cuts, burns, or exposed wiring.
  • Check the plug for signs of overheating.
  • Replace the power cord if it is damaged.

6. Electronic Control Board

A failed control board can develop electrical shorts that cause the microwave to trip the breaker.

What to do:

  • Inspect the control board for burned components or damaged traces.
  • Replace the control board if it is defective after ruling out other components.

7. Wiring

Loose, pinched, or damaged wiring inside the microwave can create a short circuit and trip the breaker.

What to do:

  • Disconnect power.
  • Inspect accessible wiring harnesses and connectors.
  • Repair or replace damaged wiring before operating the microwave again.

8. Magnetron

A failing magnetron can draw excessive current during operation, causing the circuit breaker to trip.

What to do:

  • Inspect the magnetron for signs of overheating or physical damage.
  • Replace the magnetron if it is defective. Professional installation is recommended.

Need Help Finding the Correct Part?

If you need help identifying the correct replacement part, send us your complete microwave model number and a clear photo of the appliance identification label before placing your order. Our team will verify compatibility and help ensure you receive the correct replacement part the first time.