Power Problems That Keep Your AC Condenser From Turning On

If your air conditioner doesn't turn on, there could be a problem with your power supply. The equipment needs a signal from the thermostat to trigger the condenser to turn on. If the trigger is detected, but the unit doesn't turn on, the malfunction might be in the disconnect box or with the circuit breaker. Here's how an AC repair technician might handle this problem.

Test The Thermostat Wire And Contactor

If the condenser isn't turning on, the first thing the AC repair technician may check is the thermostat wire. If the wire supplies power to the contactor, but no power comes out of the contactor to go to the capacitor, the technician can eliminate the thermostat wire as the cause of the malfunction.

Instead, the problem is with the contactor or the power supply that comes from the disconnect box. The technician can test the contactor to see if it's good. If so, the next place to look for a problem is the disconnect box.

Check The Disconnect Box

The disconnect box is a small box that's mounted on the side of your house next to the condenser. Power from the electrical panel goes to the disconnect box and then into the condenser. The purpose of the box is to provide a quick way to kill the power that is within sight of the technician, so it acts as a safety mechanism. Some boxes have pull-outs and others have fuses.

The technician can pull out the fuses and test the box with a multimeter to see if it is bad. If the box is okay, the technician can test each fuse to see if one's bad. A bad fuse can be replaced with a new fuse of the correct type, and that should restore power to your AC.

Check The Circuit Breaker

If the technician discovers there is no power to the disconnect box, the problem might be in the electrical panel instead of the air conditioner. If the circuit is tripped, the AC repair technician can turn it on and wait to see if it stays on. If the circuit flips back off, the technician has to narrow down the problem to see if the circuit breaker in the panel is bad or if there is an electrical problem in the air conditioner that has to be fixed so the breaker quits tripping.

If troubleshooting narrows down the problem to the electrical panel, you might need to call an electrician for additional help. However, if the problem is with the wiring, fuses, or disconnect box, the AC repair technician can repair or replace the bad parts so the condenser gets the power it needs to start up and cool down your house.