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A circuit breaker is an electrical switch designed to protect an electrical circuit from the excess current which will result in damage. In simple terms, its function is to detect faults and interrupt the flow of current. When circuit breakers trip, they shut down the air compressor system, and work stops.
It can be a problem when the circuit breaker constantly shuts down your air compressor. This page will provide you with the reasons as to why your air compressor keeps tripping its circuit breaker as well as providing you with existing reader problems and responses.
Table of Contents
- Air Compressor Trips Circuit Breaker
- Why A Compressor Circuit Breaker Trips
- Air Compressor Blowing Power Supply Circuit Breaker vs Motor Thermal Overload Switch?
- FAQs (Frequently Asked Questions)
- Existing Reader Circuit Breaker Tripping Problems and Responses
Air Compressor Trips Circuit Breaker
When the air compressor tank is drained down to the cut-in pressure, the pressure switch will react to this drop-in tank pressure. The pressure switch trips to passing and allows the compressor to start and run until the compressor tank pressure has reached its cut-out pressure.
When the pressure reaches the cut in, the current of electricity will flow through the pressure switch and then through the motor to start the circuit and then flow to a start capacitor to kick start the system.
Note: some small compressors may not have a start capacitor as they have sufficient current in the electricity flow to start the motor but larger compressors will require this additional “inrush current” of the start capacitor.
If for some reason the motor cannot start on your compressor, it will continue to draw power and may even pull enough amperage to exceed the capacity of the breaker and as a result, the breaker will trip.
Why A Compressor Circuit Breaker Trips
There are a number of reasons why an air compressor circuit breaker trips. These are due to:
- The air filter
- Broken extension cord
- Clogged cylinders
- Faulty circuit breaker
- Faulty motor
- Faulty pressure switch
- Failed capacitor
- Failed unloader valve
The air filter
Air compressor circuit breakers are liable to trip due to a dirty air filter. Air filters prevent dirt from entering the air pump, as dirt inside here can result in expensive repairs. It is therefore important that you change your air compressor filter often to avoid this.
If your air compressor circuit breaker trips and you check your air filter and it is dirty, replace it and try again! If your compressor still trips, you will need to troubleshoot further.
For more information visit our Compressed Air Filtration Guide!
Broken extension cord
Most air compressors are powered by electricity and therefore feature extension cords to easily connect to power supplies. A broken extension cord can cause some serious risks, potentially even fire. A fault in an extension cord will trigger the circuit breaker to trip and cut off the electric supply to the compressor and shut down its system.
Extension cords are notorious for throttling power, and therefore you may be underpowering your compressor motor. This will contribute to the motor overheating and the breaker tripping when the compressor starts.
You should leave the compressor to cool for between 15 and 30 minutes, then plug it directly into a wall socket rather than an extension cord. If your compressor starts this time and you have used it until it needs to restart, and it does so successfully then you’ve solved your problem.
Visit our What Size Extension Cord For An Air Compressor for the best extension cords available.
Note: I will always advise that you use lengthy air hose to get your compressed air to your desired work station. Using an extension cord to get the air compressor closer to where you require to use it is likely to result in damage whilst a lengthy air hose will not.
It’s possible that the cylinders inside your air compressor (if it has any), can become clogged and hinder the performance of the compressor. A faulty or clogged cylinder or multiple can certainly cause the circuit breaker to trip to prevent the air pump from undergoing damage.
Faulty circuit breaker
Let’s not ignore the fact that the circuit breaker itself could be faulty! Though they’re very high-quality parts installed in air compressors, it is possible that after years of use they become faulty.
They’re very easy to source and replace if this is the case, allowing you to restore the correct functions of your air compressor system.
Air compressors feature high-capacity induction motors that have a low amperage draw. If you have a faulty motor it can trip the circuit breaker in your air compressor system. The motor windings or any other electrical connections inside the motor may be shorting and this sudden flow of electricity pulls too many amps.
You will probably need the services of a specially trained technician to determine whether you have a faulty motor or not. We have Air Compressor Motor Guide that provides types of motors and where to buy them!
Faulty pressure switch
Though this isn’t as likely as the other reasons why a circuit breaker trips, it’s still possible! When the air pressure in the tank drops, a small diaphragm inside the pressure switch moves and forces points inside the switch to touch making a circuit. This then signals a flow of power to the compressor motor to enable it to start and pump more air into the tank.
To check if your pressure switch is faulty and causing the breaker to trip, follow these steps:
- Turn off/unplug the compressor and drain its tank of air
- Pull the cover off the pressure switch (be careful due to the presence of live terminals)
- Reset the breaker
- Watch inside the pressure switch to see if there is any arching or sparking when you turn on the compressor
If any arcs or sparks occur when you turn the compressor back on, that’s a great indication that your pressure switch needs replacing.
If your compressor is large enough and has a start capacitor, it’s likely that your circuit breaker trips due to the failing of the capacitor.
It’s a very complex process to test an air compressor start capacitor and therefore you should seek professional help to do so!
Failed unloader valve
Sometimes the unloader valve can fail and cause the circuit breaker to trip. When it fails, compressed air will become trapped over the cylinder piston and this adds to the load the compressor motor experiences on startup. The additional load may force the motor into pulling too many amps and therefore tripping the circuit breaker.
To test your unloader valve, follow these steps:
- Turn off/unplug your compressor
- Open the tank drain and drain all the air out
- Turn on/plug your compressor back in with an empty tank
If your air compressor starts and the circuit breaker doesn’t trip after doing this then it’s evident that your unloader valve is not working properly and it either needs fixing or replacing.
Air Compressor Blowing Power Supply Circuit Breaker vs Motor Thermal Overload Switch?
The key difference between an air compressor blowing the circuit breaker and the motor thermal overload switch is that the latter is solely due to the compressor motor overheating, and so, the thermal overload triggers and doesn’t allow the compressor to turn on until it has sufficiently cooled.
On the other hand, the circuit breaker may trip due to the many reasons described in this article!
FAQs (Frequently Asked Questions)
There are so many different reasons as to why your air compressor is tripping your circuit breaker. These include any of the following:
– Dirty air filter
– Broken extension cord
– Clogged cylinders
– Faulty circuit breaker
– Faulty motor
– Faulty pressure switch
– Failed capacitor
– Failed unloader valve
Yes, if your compressor goes bad and tries to draw too much electricity it will certainly trip your circuit breaker amongst other possibilities. You must aim to keep all your compressors parts in good working condition to try to avoid a tripping circuit breaker.
There are a number of reasons why this may occur, it could as simple as having a faulty motor or even a faulty circuit breaker itself. Otherwise, the air filter could be full of dirt and clogged, the unloader valve or start-up capacitor could be failing and consequently causing the circuit breaker to trip.
Existing Reader Circuit Breaker Tripping Problems and Responses
Runs For About 5 Seconds Then Blows Breaker
by Mike Weiss
(Maple Grove MN)
Emerson electric motor label, could this problem be caused by the running capacitor?
Mike, you are not giving us much to go on.
Are you running your compressor motor in 120 or 240 volt configuration?
Does the compressor run if the air tank is empty when you start it?
Are you using an extension cord if running the compressor on 120 Volts?
How old is your compressor?
What is the make, model?
Sure, it could be the capacitor, and you can see the page on this site about how to check that.
Otherwise, it is difficult to say without a lot more info. Please add more info so we all can try to help.
4hp 13 gallon air compressor trips breaker
Got a 4hp 13 gallon oil less air compressor the problem is that it builds air fine but when it gets low on air and tries to kick back on it just hums and trip the breaker any clues? the motor I’m guessing? please help
Jill, turn off the compressor. Drain the tank. Turn the air compressor back on. Did it start OK? Respond as a comment here, please so if it did not start we can dive further into the reasons.
Compressor will not restart and trips breaker
My air compressor will not restart after the first start up cycle. I’ve changed pressure switch with new unloader valve. ive changed check valve. I’ve tried multiple higher amp ac circuits. compressor acts the same after first cycle of pressure in tank it trys to restart after low pressure level trips, compressor tries to start and eventually trip breaker
OK, you don’t say after you changed the pressure switch (probably not needed) and unloader valve, whether when the compressor comes up to cut out pressure and stops your unloader valve actually is unloading the compressor.
You also do not describe your power supply to the compressor, nor it’s make & model and HP.
It is hard to help you diagnose the problem without these details.
So, if the compressor starts with the tank empty of air, and the unloader valve is working on high pressure cut out, provide more details as a comment here and I’ll try to help you figure out what the problem is.
30 gallon craftsman
Started the other day kicked breaker found bad capacitor, changed it, now compressor runs for few seconds then kicks breaker
Model number? How many caps on this motor? Anything new aside from the problem? Perhaps, start a new thread in the Craftsman forum, and include the model number for sure, along with any more info. Thanks.
Compressor motor blows breaker
by: Mike weiss
Bill! The compressor is a Black Hawk 5 HP as I recall, Running on 120V. I took the belt off the pump just to make sure the pump wasn’t holding it back. even without any resistance the motor blows the breaker after a few seconds…Mike
Hi Mike… OK Black Hawk I believe, don’t believe it’s a 5HP if you are powering it with 120 volts.
Regardless, if you are not using an extension cord and the problem persists with no load on the motor, then yup, the first thing to look at is if the start and run (might be two – might be two in one) capacitors are OK. See that page for details and then update us if that was the issue, would you?
A number of existing reader circuit breaker problems and responses for varying compressor brands and models are also accessible on this site:
If you have any questions regarding an air compressor circuit breaker tripping, then please leave a comment below, with a photo if applicable, so that someone can help you!