Furnace Blower Motor Capacitor Test

Buy when you get up there there are a couple of wires coming off the blower motor.

Furnace blower motor capacitor test.

Set your voltmeter to the capacitor. How to test start capacitors on furnace blowers. Look at the wiring digram on the back of the furnace. If you notice your furnace s motor cycling frequently you should test the capacitor.

Locate the capacitor inside your appliance capacitors are metal tubes that store an electric charge usually found near a motor in the appliance. Using a capacitor tester to test the capacitor. Check the capacitor rating on the side of the unit. Remove the wires that are connected to the terminals.

Inspect the capacitor visually for signs of damage. Remove the wires that are connected to the terminals. Faulty capacitors lead to overheating intermittent motor operation humming noises or even outright blower motor failure. So the capacitor plays a big role.

First the power supply should be shut off then the two terminals on the capacitor should. A furnace usually uses a run capacitor to maintain a relatively constant voltage supply to the blower motor. A capacitor helps the motor run and gives it more torque. For example if your capacitor says 50 5 the acceptable capacitance range is 47 5 to 52 5 f.

I dont know how savy you are. A faulty capacitor will not be able to hold the charge necessary to run the blower motor properly. If it not you probably have a failed capacitor. Although only pros should test or repair capacitors you can examine your.

When the motor generally goes south the motor itself it will trip the breaker. This will cause the motor to run slowly causing excess heat. Failed capacitor would be my guess if no blower. Excessive heat in the motor can cause the motor to malfunction.

If the capacitance number went up infinitely to the limit of your multimeter the capacitor has shorted out and should be replaced. If a motor doesn t have the torque to turn the blower wheel or the fan belt it won t start. Set your voltmeter to the capacitor setting and connect the meter to the terminals on the capacitor. Check the capacitor rating on the side of the unit.

If you re concerned that your furnace capacitor isn t operating properly you can test it by following a few simple steps. Inspect the capacitor visually for signs of damage.