Common Reasons Your Microwave Keeps Tripping the Breaker (and How to Fix it)

By Nick Evans •  Last Updated: 04/25/22 •  9 min read

Microwaves use a lot of electricity, especially when they’re heating your food. For this reason, your microwave might be tripping your breaker.

We’re going to take you through some of the common reasons this occurs and show you how and why your microwave is tripping the breaker.

Along the way we lay out solutions you can try before replacing the microwave.

Read on to learn everything you need to know about your microwave tripping your circuit breaker.

What Is a Circuit Breaker? 

A circuit breaker is a safety device that protects an electrical circuit from damage. Circuit breakers are found in most homes and interrupt the flow of electricity to prevent a short circuit or overcurrent.

These devices are similar to fuses but can be reset instead of replaced. Moreover, circuit breakers are vital pieces of equipment that protect homes and appliances from fires and other electrical issues.

In modern homes, circuit breakers control how much electricity is sent to each room and allocate the proper distribution of electricity. Overall, the circuit breaker manages the electricity that’s sent to your home from electric companies. 

How Long Do Circuit Breakers Last?

Circuit breakers are more durable than fuses because they can be reset. Plus, they cut off the supply of electricity to avoid damage to the circuit breaker and your home. For this reason, most circuit breakers have an average lifespan of between 30 and 40 years. If there are minimal electrical problems, some breakers can last for up to 50 or 60 years.

Microwave Breaker Problems: Causes and Solutions

There are several ways in which a microwave can trip a circuit breaker. Unfortunately, this makes it hard to determine what the cause of the problem is. To help you narrow down the possible causes, we’ll take you through each of the ways a microwave can trip a breaker. We’ll also provide you with some tests you can perform to help you figure out what the problem is.

The Breaker Is Overloaded 

The most common way for a microwave to trip a breaker is for the circuit to be overloaded. Many things in your home will be connected to different circuits to prevent the circuit breaker from becoming overloaded. In general, most circuits can handle an amperage of 20 (20 amps).

The average microwave has an amperage that’s between 10 and 15, so most microwaves won’t overload the circuit unless they’re sharing a circuit with other appliances.

If you check the breaker and your microwave is not on its own circuit, we recommend adding it to its own circuit to prevent the breaker from being overloaded.

On the other hand, a malfunctioning microwave can also trip the breaker and cause the circuit to overload. While this is less common, if your microwave is damaged and not drawing power correctly, it can damage the circuit breaker, cause wires to melt, lead to fires, and more.

Your Microwave Is Not Working 

In some cases, it’s challenging to determine if your microwave is not working properly. Therefore, simple multimeter tests might not be enough.

For these cases, we recommend testing out the microwave on high-amp outlets to see if the breaker still trips. When it comes to testing your microwave, a multimeter is your best friend. It’s a tool that measures electrical currents and the resistance of electoral currents. 

Microwaves have many components, so it can take a few tests to help you determine what part of the microwave is faulty. We’ll have some common microwave issues explained below.

Read Also: White Smoke from Microwave (How to Fix)

The Safety Latch for Your Microwave Door Is Broken 

Most microwaves come with a handful of safety latches. These latches lock the door in place to prevent it from opening if the microwave is heating foods or beverages.

Safety latches are important because they prevent the microwave from harming a circuit and yourself. 

There are a few ways to determine if the safety latches on the microwave are broken.

The best method is to use a multimeter tool. Place the tool on the ohm setting and disconnect the electrical connectors. Then, place the multimeter tool on the terminals of the microswitches.

If you’re not getting a continuous reading on the multimeter, one or more door switches is faulty. Another test is a simple one. If the light stays on when the door is closed, the door latch switches are faulty.

Unfortunately, having faulty door latch switches can cause a fuse to blow out. This event leads to the circuit breaker being tripped.

If this occurs, you’ll have to look for a new microwave or replace the door latch switches. If your microwave is a newer model, you can find the parts online from the manufacturer. 

Moisture On the Motor 

The turntable in a microwave is powered by a motor. While the motor is protected against moisture, sometimes moisture from food and water can seep through the shield and into the motor.

When moisture reaches the motor it creates electrical problems that result in tripping the breaker. Moisture building up in the motor can also cause a fuse to blow and damage the microwave.

There are a few ways to test the turntable motor. The simplest is to see if the motor is turning.

If the turntable is not rotating properly, there is a good chance the motor is damaged and causing electrical problems. You can also test the turntable with a multimeter.

To do so, unplug the microwave and disconnect the turntable motor from the capacitor and other components.

Then, use the multimeter tool to measure the ohms of the motor. The ohms should give you a reading between 6 and 12. If the reading is not between those numbers the motor is likely faulty and causing your breaker to trip.

Defective Capacitor 

The capacitor is a component of the microwave that’s designed to store electrical energy. This energy is sent to the magnetron to create microwave radiation that heats your food or beverage.

You can tell if the capacitor is defective by checking for a humming sound.

The humming sound can be quiet or loud depending on how badly it’s damaged. If the capacitor of the microwave is broken, it will trip the breaker or a fuse will blow.

That said, there are methods to test the capacitor.

Before doing so, make sure the microwave is unplugged and that it’s been turned off for a few minutes.

Then, remove the connectors from the capacitor. From there, connect the multimeter and test the ohm of the capacitor. If there is no reading or a small reading, the capacitor is defective and the cause of the problem.

Magnetron Malfunction

The magnetron is responsible for converting electrical energy into microwave radiation. Microwaves use microwave radiation to speed up water molecules, which heats your food or beverages.

While magnetrons are durable components, they’re also complex components that can fail when used for many years.

If your microwave magnetron fails, it won’t heat anything within the microwave. To test this, you can place food items that contain water or even a cup of water into the microwave.

If the microwave doesn’t heat the item, there’s a good chance it’s a magnetron problem. You can also use a multimeter tool to test the magnetron.

If it doesn’t have an ohm resistance between 2 and 3, there’s a good chance the magnetron is malfunctioning. In these cases, we recommend replacing the microwave.

Electrical Supply Problems 

Microwaves require a lot of electrical energy. If there is a problem with the electrical supply to the microwave, this can cause electrical problems and trip the circuit breaker.

The best way to determine if your microwave is having electrical supply problems is to check the power outlet.

If the power outlet looks damaged in any way (melting is a common one) then there is a good chance that the microwave is having an electrical supply problem.

If your microwave is having an electrical supply problem or if the plug is stuck within the power outlet, we recommend contacting an electrician.

We also recommend turning the microwave off immediately and disconnecting it from the circuit. This will prevent further damage to your home’s circuits and other electrical issues.

Tips to Prevent a Microwave From Tripping Your Breaker 

The best way to prevent your microwave from tripping the breaker is to have it on its own circuit. Having your microwave on its own circuit will prevent the microwave from overloading the circuit.

To prevent your microwave from tripping the circuit if it’s on its own circuit you need to make sure it’s working properly. Be sure to check for the following issues listed below.

If your microwave is suffering from any of these problems, it’s best to repair your microwave or replace it before connecting it to a circuit.

Final Thoughts 

If your microwave is tripping your breaker that’s a bad sign. Not only can it damage your microwave but it can damage your home and other appliances. For this reason, it’s important to know if the microwave is responsible sooner rather than later. If you follow the tests we mentioned above you’ll have enough information to make a diagnosis and a decision about what to do with the microwave and circuit breaker.

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