Why Is My AC Tripping My Circuit Breaker?

You turn on the air conditioning to fight the latest heat wave, but it shuts off unexpectedly. The breaker tripped. You reset the breaker and try again, but the AC circuit breaker keeps tripping.

You can’t stay cool if your AC unit won’t stay on. Let’s take a look at some of the most common issues that may cause your breaker to trip, including:

• Clogged air filters
• Dirty condenser coils
• Low refrigerant
• Broken fan motor
• Malfunctioning compressor
• Electrical panel issues
• Faulty breaker
• Overloaded circuit

While some of these issues are a quick, do-it-yourself fix, most are better handled by a professional. If changing the air filters doesn’t fix the problem, call an HVAC pro for experienced help.

Clogged Air Filter

If your air filter is severely clogged, it could cause your AC unit to keep tripping the breaker. Although this doesn’t directly affect your unit’s electrical systems, it does impact airflow. Reduced airflow causes your air conditioner to run longer and harder to cool your home, potentially leading to overheating and the repeated tripping of your circuit breaker.

Dirty Condenser Coils

Your electrical system is calibrated based on the normal function of your air conditioning unit. Dirty condenser coils can cause your unit to draw more power than expected, overloading the system. This is particularly true if you have an older, lower-capacity panel box. If your home is always operating at near capacity, anything that makes your appliances work harder can result in a tripped breaker.

Low Refrigerant

A refrigerant leak in your AC system can indirectly cause the circuit breaker to trip. When there’s adequate refrigerant, your AC should cycle 2 to 3 times per hour with 15 to 20-minute cooling cycles. However, if your refrigerant is running low, the cycles may extend, reducing the system’s ability to cool down and increasing the chances of overheating and tripping the breaker.

Broken Fan Motor

A broken fan motor can cause an AC breaker to trip, either directly or indirectly. For example, if the fan has an electrical fault, it can overload the system directly. A short in the motor affects the entire system. If the fan motor simply wears out but the electrical components remain in good condition, it can lead to indirect shorts due to overheating. The fan keeps the system distributing cool air. If it fails to run, the ambient temperature in your home won’t change, causing your AC unit to run nonstop.

Malfunctioning Compressor

The compressor is a power-hungry component of your AC system. If it has an electrical fault, it can easily overload a circuit, tripping the breaker. Internal short circuits can lead to electrical arcing or spikes in current, both of which can trip a circuit. A mechanical failure in the compressor can also cause power surges that trip the breaker. If the rotor won’t move, it means the unit pulls way more power than expected during startup, which causes an electrical shutdown for safety.

Electrical Panel Issues

Many homes have electrical panels as part of their original construction. If your home is newer, then there’s unlikely to be an issue. However, if your home is more than 25 years old, your electrical panel might require professional maintenance to stop an AC breaker that keeps tripping.

Faulty Breaker

If your AC unit doesn’t have any identifiable problems, the issue could originate with the breaker. Circuit breakers are designed to handle a specific load. If your AC unit regularly exceeds that load, the breaker might have extra wear and tear. Also, circuit breakers only last about 30 to 40 years. If your home is older, it may be time to replace the aging breakers.

Overloaded Circuit

Energy capacity is another issue that can cause a frequently tripping breaker. If your panel box only supports 100 amps and all of your appliances combined exceed that number, it’s no surprise that your circuit breaker trips frequently. Consider upgrading your panel box to address this issue, which requires professional help.