Why Does My Air Compressor Keep Blowing Fuses?

Why Does My Air Compressor Keep Blowing Fuses?

Picture the scene; you’re happily working away in your workshop and yet again, that damn air compressor blows a fuse. It’s an inconvenience to say the least but if you’ve got a lot to get done, the last thing you want is to have to keep changing fuses and doing unnecessary maintenance. But before you can fix the problem, you need to know what’s causing it. So, if you’ve been scratching your head and asking why does my air compressor keep blowing fuses, we’ve got your back.

There could be several things that are causing your air compressor to malfunction in this way. These include using an extension cable, a faulty unloader valve or a faulty pressure switch.

But there’s no need to worry. For the most part, there is an easy fix and in this guide, we will be looking at what’s causing the problem and how to solve it.

Understanding Your Air Compressor

Before we get into the nitty-gritty of why your air compressor is causing you problems, it’s worth getting a basic understanding of how these tools work. Generally speaking, most people have problems with blown fuses because of a shortage in the flow processes that allow the air compression to function as normal.

When an air compressor is working correctly, the pressure would be drained to a certain point and up until this point, the air compressor would be running normally. Once the pressure cut level is reached, the air compressor would automatically stop working. It does this thanks to a pressure switch which will close as the compressor nears its pressure cut. As this happens, a circuit is completed and power is able to flow to the motor.

But there are cases when this doesn’t happen and the motor won’t start. However, it will still continue to try to take power and in some instances, it’ll try to take too much. So what happens? The breaker reaches its max and will trip when you restart the air compressor.

Common Problems That Cause An Air Compressor To Blow Fuses

Now that we understand how our air compressors get into this sticky situation, let’s take a look at some of the things that can throw the system off track. Keep in mind that the problem could be one or a combination of the following things so it’s worth giving your compressor a thorough check over before attempting to continue to use it.

Using An Extension Cable

Extension cables can be a lifesaver in many situations. If your power cord won’t reach where you need to be, simply plug in an extension and you’re good to go, right?

Well, yes in many cases this is true but with an air compressor, extension cords or power bars are not always the ideal solution. You see, it’s no secret that an extension cord can override the mains and determine how much power is delivered. Moreover, the power is often more limited than when an electrical item is plugged directly into the wall socket.

As a result of this, as your air compressor tries to take more and more power, the limit is reached far sooner. This can also cause a limited amount of power to be delivered and that can cause problems with overheating. So then what happens? Your air compressor blows the fuse.

Where possible, we would always advise plugging your air compressor directly into a wall socket. For many cases, this will immediately solve your problem, provided that all other components of the device are working as they should.

Valve Problems

Another common issue with air compressors that blow fuses could be with the unloader valve. There are times that this valve will simply fail (the reasons for this would need to be investigated separately) but when this happens, small amounts of air become trapped in the piston of the cylinder.

Once this occurs, a lot of pressure is put on the compressor’s motor and this can result in a power surge. When this happens, you’ve got a blown fuse. Therefore, it is important to check that your unloader valve is in good working order and if it isn’t, you’ll need to replace it.

Problems With The Pressure Switch

Generally speaking, the pressure switch isn’t likely to be the cause of the problem but that isn’t to say that it’s not possible. If it does, it’ll be because the switch has shorted and this will then cause a chain reaction resulting in the air compressor blowing the main fuse.

You won’t know whether this is the case without removing the air compressor cover and doing some visual checks. You’ll need to disconnect the air compressor from the power source and completely drain the tank. Now take the cover off and reset the breaker. You’ll need to pay attention here and check whether there are any sparks. If there are then it is likely the pressure switch that has caused the blown fuse. Again, you can replace this as a DIY project and pressure switches are very affordable.

Problems With The Motor

As with any other type of tool, your air compressor will have a limited service life. One of the most common problems is overuse or an old air compressor whose motor just isn’t what it used to be. When the motor doesn’t work as expected, this can result in constant blown fuses.

There are many reasons that the motor may be experiencing problems including general wear and tear, windings that have shorted, loose wires and many other things. Give your motor a good check to make sure that this isn’t the culprit and make the necessary repairs when you need to. Let’s take a closer look at some of the main motor problems. Keep in mind that there are different types of air compressor motor so this advice is tailored to 115v motors which are most common.


In your air compressor motor, there is a run capacitor and a start capacitor. If either of these fail then it could cause a blown fuse. Normally, the problem here is overheating but you can check this by looking at the temperature value found on the nameplate. If it gets any hotter than this, then you’ll likely face problems.


Another common issue where blown fuses are concerned is that there may be a problem with the internal wiring. You probably won’t have problems with shorting when initially using the air compressor as there hasn’t been enough chance for heat to build up.

However, once it has been running for a while, it’ll start getting hot and this causes the wires to expand. That’s not a problem in itself but it could mean that when wires touch one another, this causes the circuit to short. In this case, you may need to have your air compressor motor looked at by a professional. Either that or bite the bullet and replace it entirely.


Isn’t it frustrating when our tools don’t work as they are supposed to? Many people have felt the annoyance of an air compressor that just keeps blowing a fuse. But most of the time, the solution is simple.

Why does my air compressor keep blowing fuses? Well, you’ve either got a problem with the motor, valves or pressure switch. If it’s none of those, it might be worth considering how you are powering your device as something as simple as using an extension cable could be the root of the problem.

Why Does My Air Compressor Keep Blowing Fuses?

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