Condenser fan motors take heat out of the air conditioning system by drawing air
through the condenser coils (the fins that wrap around the unit). If your fan motor
fails, the compressor will shut itself off and no cold air will be delivered to the
There are several important things to look for when replacing a fan motor.
1. HORSE POWER - This is usually a fractional number ranging from 1/10th to 3/4.
This is how powerful the motor is.
2. RPM - Revolutions Per Minute. Most fan motors run at 1075-1100 RPM. Some
run at 825-850 RPM. It's important to replace with a motor that has similar RPMs.
3. SHAFT DIAMETER - Most fan motors have a 1/2" shaft diameter. Some have a
5/8" shaft diameter. We currently do not carry any 5/8" shaft motors.
4. AMPS - Amps are usually shown on the motor as a decimal number like 2.1 or
3.5 sometimes with an "A" before or after. This is the overcurrent protection of
the motor. The rule of thumb is that you want to stay within 10% of your old
motor's rating. If that is not possible then it is ok to upgrade to the next HORSE
POWER size up. It will usually have a higher amp rating which is ok. You would not
want to downgrade to a lower size.
5. FRAME SIZE - Most residential AC units use a frame size of 48z or 48y for fan
motors. That translates to a motor diameter of 5-1/2". This is currently the only
frame size we carry.
6. MOUNTING STYLE - There a several different mounting styles. If possible, you
will want to try to reuse the original mounting bracket.
The most common mounting style is STUD MOUNT. The motor is attached to the
unit via 4 threaded studs that protrude from the back of the motor. They are
inserted through matching holes in the grille of the condenser unit and secured
with nuts on the top.
Some units use a round bracket that wraps around the motor called a belly band.
The belly band is tightened around the motor and secured to the grille via legs
that flare out from the bracket. There are several different shapes and sizes that
these come in.
Another mounting system (used in Rheem and Ruud units) is a square plate that
screws to the sides of the motor. This requires a special motor that has screws
tapped into it already. See the "Rescue" motors below.
7. RUN CAPACITOR - Your old motor may use a different capacitor then the
replacement motor. It is recommended that whenever you replace a
motor you should also buy a new capacitor.
8. ROTATION - Motor rotation is determined by looking at the lead end (where the
wires come out) of the motor and find which way it spins to deliver air. Some
motors spin counter-clockwise lead end. Some spin clockwise lead end. All of the
motors listed below are factory set for counter-clockwise lead end rotation BUT
can easily be reversed to clockwise lead end rotation.
SELECT A FAN MOTOR REPLACEMENT Remember to add a run capacitor from the recommended accessories list.