How to Disassemble an AC Fan Motor
When an alternating current fan motor malfunctions, it may be due to worn bushings. The excessive play between the motor shaft and bushing, or the rotor binding against the stator can cause the fan motor to spin slowly or operate nosily. This problem can be repaired by disassembling the motor and repairing or replacing the defective parts.
Removing the Fan Motor
Remove all electrical connections to the fan motor and remove the mounting screws with the adjustable wrench.
Remove the fan motor. Place it on a work bench or on a flat surface.
Use the screwdriver to place a mark on the motor housing and end bells on either side. This is done to correctly realign the motor components during reassemble.
Apply firm pressure to separate the end bells on either end with a flat screwdriver. You may need to use a mallet to tap off the end bells with the screwdriver.
Firmly hold the end bells and pull from the motor shaft at the top of the motor. Firmly hold the bottom end bell and pull from the motor.
Place the end bells on a flat surface. Hold the motor shaft in one hand and slide free from the motor stator.
Inspect bushings for wear and stator windings for burnt marks. Repair and reverse steps to reassemble.
Removing the Fan Blade
Select the proper size Allen key, and loosen the securing nut from the shaft. Gently tap the fan blade until it slides free from the shaft. If suitable, the puller can be used to remove the fan blade.
Secure the puller around the fan blade and place the puller screw to the end of the shaft. The fan blade will be pulled off slowly.
Place the fan motor on a flat surface with the nuts of the retaining bolts facing up. Use the adjustable wrench or ring spanner to remove the nuts from the retaining bolts.
Removing the Retaining Bolts
Place the fan motor with the shaft facing up. Remove the nuts from the bolts with the adjustable wrench.
Tap the bolts out from the motor frame with a wooden mallet or a block of wood.
Pull the bolts free from the motor housing with pliers.
Removing the End Bells and Rotor
Separate the end bells from the stator by lightly tapping with the flat screwdriver.
Pull both ends of the bells free from the motor.
Hold the shaft firmly with one hand and remove the rotor from the inside of the stator.
The motor is now disassembled.
- "Electricity & Controls for Heating,Ventilation, & Air Conditioning"; Stephen L. Herman, et al; 1996
- In order to disassemble the fan motor, the fan blade must be removed from the shaft.
- When disassembling a fan motor, lay out parts on a flat surface in an orderly manner to avoid confusion during reassembly. Place parts from the left side of the motor on the left. Place parts from the right side of the motor on the right.
- Switch off power before removing any electrical components.
- When operating a motorized appliance, always keep hands clear from rotating parts.
- Be careful not to damage the threads on the retaining bolts when tapping with a wooden mallet.
Martha Richardson began her journalism career as a newspaper reporter in 1992. She has written articles for the Printmaking Council of New Jersey and featured community organizations on "Access New Jersey." Richardson has a Bachelor of Arts in journalism. She graduated from Rutgers University in 1994.
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