10 Reasons Why Your Air Compressor Keeps Tripping the Breaker

Few things are as frustrating as trying to use your air compressor only to have your circuit breaker trip – especially if it happens over and over again. To make matters worse, there are numerous possible causes, many of which can be difficult to diagnose. So this article will cover the many possible reasons your air compressor is tripping your circuit breaker, how to diagnose them, and what to do about them.

A Word On Circuit Breakers

A circuit breaker is a switch designed to protect an electrical circuit (and the devices drawing power from it) from damage due to faults, shorts, or excessive current. They are located in your electrical distribution board (aka breaker box). When an electrical anomaly or overload is detected, the breaker will automatically “trip,” cutting off power to the circuit. 

This gives you some idea of what’s going on when your air compressor trips the breaker – it’s usually due to an overload or electrical fault of some kind.

Immediate or Delayed Breaker Trip?

The first thing to keep in mind when troubleshooting a circuit breaker trip is when the breaker trips. Does it happen as soon as you turn it on or after it’s been running for a few seconds or more? The answer may point you in the direction of the root cause. That being said, some issues may cause either an immediate or delayed trip.

With that in mind, we’ll examine the possible causes in each scenario separately.

Air Compressor Trips The Breaker As Soon As It Starts

First, let’s look at what might cause your air compressor to trip the breaker immediately on startup. (Note: this means when you initially turn it on, not when the pump kicks back on automatically during use – we’ll explore that scenario in the next section.)

Reason #1 Your Circuit is Overloaded

Before looking at the air compressor itself, it’s best to rule out issues with your circuit. One of the most common causes of a tripped circuit breaker is a simple overload of the circuit. If you have multiple devices plugged into the same circuit, turning on your air compressor may simply put it over the edge – air compressors tend to draw a lot of power when the motor starts up. This issue may not always occur immediately on startup and may be accompanied by flickering/dimming lights.

Solution: Find out what other appliances or lights are on the same circuit and try unplugging other devices or plugging your compressor into another circuit with fewer (or no) other devices or lights connected to it – the closer to the breaker box, the better. If this solves the problem, the likely cause was an overloaded circuit.

Reason #2 Faulty Breaker or Wiring Issue

The issue may also be with the breaker itself or a wiring issue somewhere else in the circuit. Breakers can wear out over time, so if you have very old breakers, this may be the issue. A loose or damaged wire may also be to blame, whether in the breaker box, outlet, or compressor power cord – or anywhere in between. A damaged extension cord may also be to blame (more on extension cords later).

Solution: Inspect visible cords for damage. If using an extension cord, try plugging directly into the wall instead; if the compressor power cord is damaged, you may need to take it to a professional for repairs. Test the circuit for continuity using a multimeter, or replace the breaker. This can be dangerous, so if you’re not comfortable and familiar with electrical work, don’t hesitate to hire an electrician.

Reason #3 Short-Circuit/Failed Capacitor/Loose Wiring In Compressor

If the circuits are fine and aren’t being overloaded, you may have a short in your compressor. This can be caused by a loose electrical connection, failed capacitor, or shorted motor windings (the coiled copper wires on a motor). Any of these issues can create an overdraw of amps, which will cause the breaker to trip.

Solution: With the compressor turned off and unplugged, check all electrical connections in the compressor head and tighten if necessary (your user manual should have instructions on how to do this). If this doesn’t solve the problem, you’ll have to test the motor windings and capacitor(s) to ensure they’re working properly. Again, unless you have experience with this, you’re probably better off taking it to a motor/compressor repair specialist to have this done.

In some cases, the motor or pump may simply be on its last leg, particularly if it’s very old. If so, you’ll likely be better off replacing the whole compressor.

Air Compressor Trips Breaker After Running for a Few Seconds (Or Longer)

It’s typically more common for an air compressor to trip the breaker after running for a short time or as the motor kicks on a second time to maintain pressure in the air tank. Let’s look at the possible causes of this.

Reason #4 Dirty Air Filter or Cooling Components

If your compressor’s air intake filter is clogged with dirt and dust, it can strain the motor, causing it to draw more amperage than normal. If this excess power draw exceeds the breaker’s capacity, it will trip the breaker. Similarly, if the cooling fan intake grate or any other air pathways are clogged with gunk, the motor may overheat and cause the breaker to trip.

Solution: Clean or replace the air intake filter. Clean any other air pathways or cooling apparatus such as intake vents and cooling fins (compressed air and a microfiber cloth work well). Run the compressor again to make sure the problem is solved.

Reason #5 Low Oil/Too Much Oil

If your compressor is oil-lubricated, make sure it has the correct amount of oil in it. Too much or not enough oil can both cause the pump to struggle and overdraw power, resulting in a tripped breaker.

Solution: Check the oil level to ensure that it’s right where it should be according to the instructions in your user manual. Add or drain oil accordingly and try to run it again. If oil has entered your air chamber you may need to wait a day or so to let it drain back down into the sump.

Reason #6 Extension Cord/Power Strip

Air compressors and extension cords don’t get along very well. Most extension cords aren’t rated for the amperage draw of compressor motors, which means the motor will be underpowered. This can cause the motor to overheat and trip the breaker. The same goes for power strips – and if several devices are plugging into the same strip, it can overload the circuit.

Solution: Plug the air compressor directly into a wall outlet or use an extension cord that’s rated for your compressor’s amperage (and the shorter, the better). In general, it’s always better to use a longer air hose instead of an extension cord.

Reason #7 Clogged Cylinder

If one or more of the pump cylinders has become contaminated with grit or rust, the piston(s) may not be moving freely, which can result in overheating or overdrawing of power. This can also occur with rotary screw-style compressors. 

Solution: If possible, try to crank the motor drive by hand (with the unit unplugged). If it’s stiff or stubborn, the issue may be a clogged or corroded cylinder or mechanical element inside the pump. You’ll likely need to have this repaired by a professional. In some cases, you may need to replace the pump, compressor head, or entire compressor.

Reason #8 Damaged/Improperly Tensioned Belt

If your compressor uses a belt drive system, the issue may simply be that the belt is worn out or not tensioned correctly and is putting undue strain on the motor.

Solution: Inspect the belt for wear and tear; check for proper tension. Replace or re-tension the belt per your user manual’s instructions.

Reason #9 Faulty Unloader Valve or Check Valve

An unloader valve is a crucial component of an air compressor. When the tank reaches its pressure limit and the pump stops, the unloader valve releases any air trapped in the air chamber above the piston. If this valve malfunctions, the air will remain trapped and increase the load on the motor when it restarts to maintain tank pressure. This increased load can cause a spike in amperage draw and trip the breaker.

Similarly, compressors have a check valve that prevents air in the tank from flowing back into the air chamber. If this malfunctions (stays open), air from the tank will reverse course into the air chamber and overload the piston – again, possibly causing a tripped breaker.

Solution: Unplug your compressor and drain all of the air out of the tank. Then, plug it back in and turn it on with an empty tank. If the breaker trips while the tank is filling, it’s likely the check valve. If it doesn’t trip until the pump kicks on a second time (to maintain tank pressure), it’s most likely the unloader valve. In either case, the solution is to replace the valve in question.

Reason #10 Faulty Pressure Switch

If the breaker trips as the pump restarts to maintain tank pressure, another possible cause is a faulty pressure switch. When the tank is drained to a certain level, the pressure switch sends a signal to the motor, telling it to kick back on and pump more air into the tank. 

If the contact terminals inside the pressure switch are worn or loose, it may create a short-circuit that trips the breaker.

Solution: Unplug the compressor and drain the air tank completely. Remove the cover on the pressure switch to expose its internal components (be very careful – you’ll be exposing live contact terminals that can shock you). Plug the compressor back in and turn it on, keeping an eye on the terminals. If you see any arcing or sparks, you have a faulty pressure switch. In this case, simply replace the pressure switch.

In Conclusion

As you can see, there are numerous reasons your air compressor might be tripping the breaker. But with the help of this guide, you should be able to solve the problem with a little investigation and experimentation. However, always follow the safety precautions detailed in your compressor’s user manual and never attempt tests or repairs that you’re not comfortable with – especially where electrical components are concerned.

Justin

Justin is a full-time blogger with a passion for anything DIY. When he's not hanging out with his wife and son, you can find him putting the finishing touches on yet another home project he's taken on. He's also the creator of AllAboutAirCompressors.com.