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When an air compressor’s circuit breaker trips, it will shut down the entire air compressor system, forcing any projects you’re working on to come to a halt. When a Sears air compressor trips breaker, it can be a worrying issue, as you’ll no longer be able to use out of your air tools.
Therefore, it is important to understand the reasons why your Sears air compressor keeps tripping its breaker, and so, this article will provide you with all the relevant information, along with existing reader questions and responses.
Table of Contents
8 Reasons Your Sears Air Compressor Trips Breaker
Here are 8 of the most common reasons your Sears air compressor is tripping breaker, along with a little description on each!
Broken Extension Cord
A fault in an extension cord will contribute to the motor overheating, triggering the circuit breaker to trip and cut off the electric supply to the compressor and shut down its system. Not only this, but, a broken extension cord is capable of causing some serious risks, potentially even leading to a fire.
Clogged Air Filter
Air compressor circuit breakers are liable to trip due to dirty or clogged air filters. Air filters prevent dirt from entering the air pump, as dirt inside the pump can result in expensive repairs. It is, therefore, very important that you change your air compressor filter frequently to avoid these repairs.
Clogged Cylinders
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.
Failed Capacitor
If your compressor is large enough to have a start capacitor, it’s possible that your circuit breaker is tripping due to the capacitor failing.
Failed Unloader Valve
When the unloader valve fails, compressed air will become trapped over the cylinder piston and this adds to the load the compressor motor experiences on startup. This additional load may then force the motor into pulling too many amps, and therefore, tripping the circuit breaker.
Faulty Circuit Breaker
Although they tend to be of very high quality when installed in air compressors, it is possible that after years of use the circuit breaker itself may become faulty and trip.
Faulty Motor
Air compressors feature high-capacity induction motors that typically have a low amperage draw. The motor windings or any other electrical connections inside the motor could be shorting, and this sudden flow of electricity pulls too many amps than required, resulting in the tripping of the circuit breaker.
Faulty Pressure Switch
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. A faulty pressure switch sending the wrong signal of flow can cause the breaker to trip on an air compressor.
For more detailed information on why an air compressor circuit breaker trips, visit our guide!
Reader Questions & Responses
Sears Air Compressor Trips Breaker – Sears Air Compressor Troubleshooting
Question
This is a Sears vertical 33 gal reciprocating compressor. The motor and pump turn free by hand. No bad bushing or bearings.
Response
Three things come to mind immediately, Jim.
One, make sure you are not using an extension cord, or if you must, it is an industrial, large gauge cord. Two, your unloader valve is not working. To test, unplug the compressor, open the tank drain to void tank, close the drain, plugin, and start. Does it? If so, your unloader valve may have failed, and the motor cannot overcome the additional load. Check out UNLOADER VALVE from the site map for details.
Three, your start capacitor may have failed. See the page on this site about testing capacitors for guidance on how to check them. There’s also a page about buying a new one if you need help there too.
Sears Air Compressor Keeps Blowing Breaker – Troubleshooting Sears Air Compressor
Question
I’ve got a sears 30 gallon 2 hp compressor, approx 2 years old. When it comes on it blows the breaker about 50% of the time. Even when it only has a few pounds in it. I changed 20 amp breaks with no change. It is a 15 amp GE commercial motor. model #5KCR49TN2450AX Ser #UYFP29. What’s my solution??
Response
Jeff, good question! 🙂
For sure you’ve got either a too great amp draw or a fault to ground.
That it doesn’t happen every time is interesting.
Do you have any other electrical appliance in the circuit that might cycle on when the compressor is starting? If there isn’t enough current to go around, that might be an issue.
You say, “When it comes on it blows the breaker about 50% of the time.” Does this mean that it starts and runs for a while then pops the breaker, or does it mean that it pops the breaker while it’s trying to start?
If the latter, I think it could be a failing pressure switch.
Post a bit more info to this thread, and we’ll continue trying to figure it out with you.
Sears Air Compressors Keeps Tripping Breaker – Sears Compressor Troubleshooting
Question
The compressor is a Sears 25 gal 5 HP portable (electric). Had been working fine, but after using it for about an hour the other day, the compressor kicked in automatically to fill the tank and blew the breaker.
The compressor runs slowly for a few seconds, then trips the breaker. With no pressure in the tank, it runs a second or two longer but still trips the breaker. I have tried several different outlets with the same result, including a dedicated 25 amp circuit, so it’s not that. I have also tried turning the pump by hand it rotates freely. The compressor is about 10 years old.
Response
Check your unloader valve. I think that it has failed, and as a result, the motor can’t overcome the additional load on startup.
Not sure what that is? Go to the sitemap page, and look up Unloader Valve for more info.
If you have any questions regarding your Sears air compressor tripping breaker, please leave a comment below, with a photo if applicable, so that someone can help you!
Can i buy a replacement motor for this compressor? The model number is 5kcr49tn2450ax motor
Probably can’t get that exact motor, but if you can send a pic of the whole motor label, probably. Failing that, the compressor model might be enough, if we can find specs on it.
Hey thanks. This is the best picture I could get.
So is this the motor portion of the pump assembly on a Craftsman 919.168700?If so, you typically would not be able to get it as a separate part.
These usually don’t quit outright.
What’s your symptom?
It would trip the breaker on 15amps. Switched to a 20amp breaker and it was ok. Last week I was filling it up (Small leak someplace) and I heard a Small pop and it would not hold pressure and sounded differently immediately while it was running. I turned it off and back on and it barely ran for a moment and now nothing.
“I turned it off and back on and it barely ran for a moment and now nothing.” Disregarding “now nothing” for the moment, from what I’ve found, this unit has at least one, and perhaps two capacitors. The run capacitor was probably going out, causing it to draw more current than it should. That’s why it worked a while longer on the 20A breaker. Please see How To Test A Start Capacitor On Air Compressor Motor – Testing Capacitors If you don’t have a meter, pretty much any cheapie will do, so you needn’t spend much unless you’re so inclined.… Read more »