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Why is my air conditioner tripping the circuit breaker?

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Last Updated on April 26, 2019


ac circuit breaker | ac circuit breaker keeps tripping

It’s the last thing you need on a hot summer day: your air conditioner keeps shutting off and the AC circuit breaker keeps tripping. You’re probably wondering what’s going on, and if there’s an easy solution. Do you need to call someone to fix the problem and if so, who should you call? The AC service company or an electrician?

Here’s the most important thing to know: your AC circuit breaker is a safety switch that protects your equipment from damage by turning off the power when an overload is detected. It also protects your safety since overloaded circuits can result in a fire. So if your AC circuit breaker keeps tripping repeatedly, this is not a situation you should ignore.

We can’t stress this enough: don’t keep resetting the breaker. You need to take action immediately to prevent expensive and potentially dangerous consequences.

AC circuit breaker tripping: WHAT TO DO FIRST

As we just mentioned, never keep turning it back on if the AC circuit breaker if it keeps tripping! You can follow the steps below once to make sure there really is a problem before continuing. Sometimes something like a lightning strike nearby can cause a one-time power surge that trips the breaker, and you’ll be fine once you turn it back on.

Here are the first steps to take when your AC circuit breaker trips:

  1. Turn the air conditioning system OFF at the thermostat(s).
  2. At your electrical panel, turn the AC circuit breaker switch to the ON position.
  3. IMPORTANT: wait 30 minutes with the air conditioner OFF. Be sure that the thermostat remains OFF so that your air conditioner’s internal circuit breaker can reset. This can’t happen if the thermostat is signaling for cooling.
  4. After 30 minutes, set your air conditioner back to COOL.

If you’re lucky, everything will work normally after this and the AC circuit breaker won’t trip again. You’re all set!

However, if the AC circuit breaker immediately trips again, or the AC won’t come back on, you have a problem that needs to be diagnosed and repaired by a professional. Read the next section for possible causes.

But what if your system seems to work ok for a little while, but then shuts off and trips the breaker again? If that happens, there’s one more thing you can try: changing your air filter. When your system filter is clogged with dust and debris, the fan motor must work harder and runs longer trying to draw air through the filter. In an attempt to do so, it may draw too much electricity and cause the AC circuit breaker to trip. Try replacing the filter to see if that makes a difference.

Don’t know how to change your AC filter? Learn more: Why and How to Change an AC Filter

Possible reasons why your air conditioner is tripping the circuit breaker

From best-case to worst-case scenario, the most probable causes of your AC circuit breaker tripping include:

  • Power surge in the area (probably due to a thunderstorm)
  • Clogged air filter
  • Dirty condenser coil
  • Loose wire, short or electrical component failure
  • Fan motor malfunction
  • Frozen evaporator coil
  • Refrigerant leaks
  • Compressor failure

We’ve covered the first 2, which you can handle on your own. The remaining issues are problems that it’s not safe to tackle yourself unless you are trained in how to work around high voltage electricity. This is a job for the professionals who not only know safety protocols but have the expertise to properly diagnose what’s wrong.

For problems causing your AC circuit breaker to trip, your best bet is to call in a qualified HVAC professional. Let’s go over the remaining causes and what you can expect when your service tech diagnoses one or more of these problems.

Dirty condenser coil

Have you been neglecting your yearly AC preventative maintenance? You may have also noticed that your system is not cooling as well as it used to. If so, a dirty condenser coil may be the culprit.

Your outside air conditioning unit has a condensing coil that does the job of releasing accumulated heat outside your building. Since it’s exposed to the elements (especially at street level or on a rooftop in the city) it can get coated with grime and debris. When that happens, heat transfer is impaired, causing your system to work harder to cool your space. Your condensing unit can draw too much power and cause the AC circuit breaker to trip.

Here’s the good news: a simple coil cleaning (done as part of a regular AC maintenance plan) can take care of this problem. Learn more from this related blog: AC Losing Its Cool? Try Air Conditioner Coil Cleaning

Loose wire, short or electrical component failure

A power surge that trips the AC circuit breaker could be caused by a simple electrical issue within the air conditioner. A loose connection, a failed capacitor, or a short in the wiring could be responsible. Those issues can be fixed easily by a professional.

Fan motor malfunction

A clogged filter is just one reason that your air conditioner’s fan motor may be drawing too much power and causing the AC circuit breaker to trip. The fan blades might be coated with grime and slowing down the fan, putting a strain on the motor. A good cleaning may be enough to resolve the issue. Or, a malfunction within the motor itself may be responsible. In this case, your AC service technician will need to replace the fan motor.

Frozen evaporator coil

If you have neglected maintenance for a long time, and you’ve got several of the problems listed above, eventually air flow is diminished within your system. That can cause the evaporator coil to freeze up, which draws excess power and can trip the AC circuit breaker. If you see ice on the coils of your inside AC unit, that’s what’s going on. In that case, be sure to keep the unit off and call in a professional right away. If you attempt to keep it running, your compressor may fail which is a very serious problem (read more about that below).

Learn more: AC Troubleshooting: FROZEN HVAC System? Don’t Let It Go

Refrigerant leaks

An older system (especially when maintenance has been neglected) can develop corrosion on the coils that leads to cracks, holes and leaking refrigerant. As the refrigerant level drops in your system, it has to work harder and run longer trying to cool your space. That can cause the unit to draw too much power and trip the AC circuit breaker.

If you’ve been noticing a slow decline in your system’s performance, this may be the cause. Your AC technician will need to find and fix any refrigerant leaks. Or, if they are numerous, replace the coil and/or refrigerant lines.

Compressor failure

The compressor is the heart of your air conditioning system and a failed compressor might mean you need a whole new system. This is why you should never keep turning on the AC circuit breaker after it trips, or ignore any of the problems described above. Ultimately the strain on the system can lead to an expensive result: failure of the compressor.

As you may have noticed, many of the problems that cause the AC circuit breaker to trip can be avoided with regular air conditioning maintenance. A small investment once or twice a year (depending on your system’s usage) can save you from major headaches down the road. Learn more from these helpful resources:

Q&A about HVAC Preventive Maintenance Contracts
HVAC Preventive Maintenance Contracts: How to Find The Right One For Your HVAC Infrastructure

Do you have older HVAC or commercial refrigeration equipment? Due to EPA regulatory changes, R22 refrigerant (the standard used to power AC and commercial refrigeration systems for decades) is being phased out come January 2020. Get informed about how this change impacts you with this information bulletin. R22 Refrigerant Phase Out: Do You Need to Replace Your AC?

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