Furnace Blower Motor Capacitor Sizing

To answer this question the panel door to the furnace will need to be removed.

Furnace blower motor capacitor sizing.

If not the capacitor or the blower motor is not functioning properly. Smith century dl1056 1 2 hp 1075 rpm 3 speed 115 volts6 5 amps 48 frame sleeve bearing direct drive blower motor. If the furnace is receiving power turn up the thermostat and see whether the blower motor starts within the next few minutes. Your furnace uses a lot of energy so to supply the extra energy needed to power the blower gas furnaces have a capacitor.

This chart shows the blower details for a 120 000btu furnace. Before checking the capacitor make sure the fuse controlling the furnace is flipped to the on position. Box type note icon none operating range blower table. Here is an example of a furnace blower motor on amazon.

Assuming a start up energy of 0 00033 joules you obtain 0 33 divided by 66 1 which equals 5 0 times 10 6 farads. Its capacitor works like a battery and stores the energy needed by the blower to work properly. A bad or faulty capacitor can exhibit many signs and symptoms. Where is a furnace capacitor located.

Like a battery the capacitor stores the extra energy that is needed to jump start the furnace blower. The blower then moves the warmed air into and through the ductwork in your house. Problem indicators what you can do. Over time a capacitor will wear out.

You can see the listing description the specifications are listed for the motor. Example furnace blower motor on amazon a o. Divide the start up energy requirement in joules of the motor by x to arrive at the capacitor size needed in farads. You must replace it so your air conditioner or heat pump continues to work properly.

The start up energy of the motor is found either in its documentation or written on the motor itself. Central air conditioners and heat pumps use capacitors. You simply measure the current amps of the motor start winding coming off of the capacitor and multiply it times 2652 on 60hz power 3183 on 50hz power and then divide that number by the voltage you measure across the capacitor. How to read your capacitor voltage and mfd for a replacement capacitors are rated by the.

But with a bad capacitor your blower cannot function well and may put your family s comfort at risk. The blower motor in your furnace blows hot air through the ducts and into your home. A capacitor keeps an electrical charge on standby to provide it to the motor when it first turns on. If you re concerned that your furnace capacitor isn t operating properly you can test it by following a few simple steps.

Before you buy a new one you must ensure it s the correct size. A furnace usually uses a run capacitor to maintain a relatively constant voltage supply to the blower motor.