To determine if your AC’s circuit breaker is tripped, locate your home’s electrical panel, often found in the basement, garage, or utility room. Open the panel and look for the breaker labeled for your air conditioning unit. If it’s tripped, the switch will be in the middle position or slightly off-center. Reset it by firmly switching it off and then back on. If the breaker trips again immediately or shortly after resetting, it indicates a persistent issue such as an electrical short or overload, and you should contact a professional to diagnose and fix the problem. Repeated tripping can also signify a problem with the AC unit itself, such as a malfunctioning compressor or motor.