Here is an example of a furnace blower motor on amazon.
Furnace blower motor capacitor sizing.
Box type note icon none operating range blower table.
You aproximate sizing of the capacitor is in the range of 4 40 mf and at the motors i have 1 1 2 2 kw the run capacitor is sized between 35 70 uf.
How to locate a furnace s start capacitor.
Hvac heating ventilation and air conditioning capacitors store electricity and help compressors and blower motors the systems that distribute hot.
If not the capacitor or the blower motor is not functioning properly.
The difference is more than 100 times is there a calculation error.
How to read your capacitor voltage and mfd for a replacement capacitors are rated by the.
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.
You can see the listing description the specifications are listed for the motor.
But with a bad capacitor your blower cannot function well and may put your family s comfort at risk.
Before checking the capacitor make sure the fuse controlling the furnace is flipped to the on position.
Divide the start up energy requirement in joules of the motor by x to arrive at the capacitor size needed in farads.
Where is a furnace capacitor located.
Smith century dl1056 1 2 hp 1075 rpm 3 speed 115 volts6 5 amps 48 frame sleeve bearing direct drive blower motor.
The capacitor will be located close to the blower motor since it is there to help the blower motor run and have wires coming from it.
Its capacitor works like a battery and stores the energy needed by the blower to work properly.
The start up energy of the motor is found either in its documentation or written on the motor itself.
To answer this question the panel door to the furnace will need to be removed.
Example furnace blower motor on amazon a o.
A furnace usually uses a run capacitor to maintain a relatively constant voltage supply to the blower motor.
If you re concerned that your furnace capacitor isn t operating properly you can test it by following a few simple steps.
The blower motor in your furnace blows hot air through the ducts and into your home.
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.
A bad or faulty capacitor can exhibit many signs and symptoms.
This chart shows the blower details for a 120 000btu furnace.
