Four Reasons Why Your AC Circuit Breaker Keeps Tripping

circuit breaker tripping

Why Does My Air Conditioner’s Circuit Breaker Keep Tripping?

Have you had an issue with your air conditioner lately where the circuit breaker at the main panel keeps tripping?  Have you gone over to the side of the house and tried to flip that breaker back on only to have it flip right back off?  In this blog, I’ll go over what could be going wrong with your AC system when this happens.

It’s not fun to come home and realize that your house, which should be a cool 75 degrees right now, is sitting at a balmy 85 degrees.  So, you go over to the side of your house and open the main electrical panel.  There you find the air conditioner circuit breaker tripped.  This means no high voltage power is getting to your AC to let it run.  Not cool.

You flip the breaker back to the on position only to have it trip again either immediately or after a few minutes or even seconds.  Now what?  So you call your local AC guy.  He comes out the next day.  Now that the system has been sitting idle for several hours, it doesn’t surprise me when the technician who comes over for a $ 100-weekend service call flips the switch on the breaker, and the system starts working again.  Hey! Someone’s got the magic touch!

You pay the smart technician the diagnostic fee, and they head out to their next call.  Meanwhile, after 30 minutes of the system running fine, the breaker trips again.  The technician is long gone, and likely can’t be back to fix it until Monday when they re-open.

How Do You Know What’s Going on with the Circuit Breaker?

If the breaker repeatedly trips after a while, there’s a problem with one of the parts inside the AC.  If the breaker trips immediately after turning it back on, there something going in the wiring.

You can’t just flip the breaker back on and hope it stays that way.  It might! But most likely, there is a reason it tripped, and that problem will come back around.  When this comes up with my technicians at Fox Family, I tell them to slow down and ask themselves, WHY did the breaker trip?  Sure, the breaker reset when you flipped it back on, but a technician finds out why it tripped.

Danger!

I want to reiterate that I’m only giving homeowners and technicians some reasons why the breaker may be tripping.  Working with high voltage can cause severe injury and even death to even the most experienced technicians.  I read about it all the time in the mechanical chat groups I’m in.

Why Do Breakers Trip?

A breaker trips when there is too much power consumption or current at any given time.  The wire from the AC to the panel heats up enough that it trips.  This stops a potentially hazardous situation from happening.  Here are some reasons your AC will cause circuit breaker tripping:

  1. The breaker could be bad
  2. The compressor or fan is drawing too many amps
  3. A short circuit
  4. Refrigerant pressure issues

The Breaker Could Be Bad

This doesn’t happen a lot.  Breakers are sturdy switches that, when heated up enough that they’re repeatedly tripping, can become weaker and trip more easily.  A new breaker can fix this problem.

The Compressor or Fan is Tripping the Circuit Breaker By Drawing Too Many Amps

Although I can’t cover every situation that might happen, I can give you a couple of common scenarios.  If a motor gets stuck and can’t turn over when the proper voltage is applied, the motor will pull a higher number of amps.  So much so that the heat builds up in the wiring and trips the breaker.  This won’t trip the breaker immediately.  But after a while (and there is no specified amount of time), the breaker can trip whenever the thermostat is calling for the AC to be on.

At the start of the cooling season, this pattern often happens with the compressor, that black cylinder at the bottom of your outdoor unit.  It pumps the refrigerant back and forth through the copper lines, much like the heart does in the body.

Assuming the capacitor is good, sometimes adding a hard-start capacitor to the circuit will help give it that boost needed to turn the motor over.  If it does, count your blessings and start saving up for a new compressor or AC unit altogether.  It’s running on borrowed time. It’s just a matter of time before your AC gives out.

A Short Circuit

Another reason for a circuit breaker to trip is because of an electrical short.  When two normally sheathed wires like a hot wire and a neutral wire touch each other when voltage is applied, it causes a major event.

The AC uses 240 volts.  This means the two or three wires leading to your motor carry at least 120 volts.  A third one can carry even more.  If two bare wires touch each other when the system is supposed to be on, a high current situation can occur, causing the breaker to trip.  As soon as the voltage is applied, the breaker will trip immediately.

Touching Wires

Another way the breaker will trip immediately is if one of the motor’s wires touch the inside wall of the compressor.  Remember, these motors have windings inside of them that help spin the motor shaft.  The windings are covered with sheathing to protect the wiring.  But it still happens, especially on older systems that have been running for ten to 20 years or longer.

Check below for a link to my video that talks about how to diagnose a bad compressor.

Refrigerant Pressure Issues

One last reason a compressor could trip the AC breaker is refrigerant pressure.  If the pressure is too high in the system, meaning there is too much refrigerant, the compressor is once again having to strain too hard to do its work.  The breaker won’t trip immediately, but over time.

This scenario doesn’t happen as often as the other events above but can look like a bad compressor. Removing a pound of refrigerant will tell you if it’s a pressure issue because you’ll see both sides of your gauges go down a little.  If this happens and the temperature split stays between 18 and 22 degrees, I would try removing refrigerant until you get the compressor amps to get back down to below the RLA, and the temp split stays within range.

Starting Over

If removing the refrigerant isn’t working as well as you’d like, it might be smart to tell the customer you’d like to remove all the refrigerant and start over with virgin refrigerant and a factory charge.  You don’t know this system’s history, and you’re not expected to, especially if the homeowner doesn’t know it or have invoices showing what previous techs have done to repair the AC in the past. It’s a fair solution for both of you.  If you do this and the compressor is still pulling high amps, and you’ve checked everything else on the system, you have a bad compressor.

Summary

These are just a few reasons why the circuit breaker in your home could trip the breaker in the main electrical panel.  If it trips immediately after turning it back on, you likely have a problem in the wiring.  If your breaker trips after a certain amount of time, something is going on with a part in the AC system.

Let a Professional Do the Fixing

I can’t tell you anybody can fix these problems by themselves.  In fact, you might not even be able to order the parts you need as it takes a licensed contractor to purchase them from a local distributor.  Let a professional come out and diagnose the exact problem and then fix the system so you can have peace of mind.

Thanks so much for stopping by and we’ll see you next time.

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