W51-12CJA1-02 – CONDENSER MOTOR (1/2, 1075, 15MFD)

TrueLine universal condenser fan motor, 1/2 HP, 1075 RPM single speed, 208-230 V, 48 frame, sleeve bearing, permanent split capacitor. Rotation is reversible and the shaft is 1/2 in. diameter by 5 in. long, with thru-bolt, shell-band or shell-screw mounting. The published run capacitor requirement is 15/370 uF, matching our stock record. Replaces W51-12CJA1-01.

Specifications published by the manufacturer. Source: manufacturer documentation.

Specs

• BrandTrueLine
• Horsepower1/2 HP
• RPM1075, single speed
• Voltage208 / 230 V, 1 Ph, 60 Hz
• Frame48
• BearingSleeve
• RotationReversible
• Run capacitor15 uF / 370 V
• MountingThru-bolt, shell-band or shell-screw
• Shaft1/2 in. dia x 5 in.

Cross-reference numbers

This part replaces the following OEM and aftermarket numbers:

• 43734
• 3734

Not sure if your number matches? Call (214) 340-9421 or bring the old part in — bench-testing is free.

How do I know whether I need CW or CCW rotation?

Read it off the old nameplate and confirm which end it is called from. Rotation is verified from the SHAFT end unless the tag says otherwise. You will see it written CWSE (clockwise, shaft end) or CCWLE (counter-clockwise, lead end), and those two describe the same spin viewed from opposite ends. Get it backwards and the fan pulls air down through the coil instead of out the top. It will run, it will just build head pressure and trip out. Many universal motors reverse by swapping the two rotation leads, but plenty do not, so check before you buy.

Do I have to match horsepower exactly?

Match it, or go up one step at most. A 1/6 to 1/5 or a 1/4 to 1/3 swap is acceptable. A 1/4 to 1/2 is not. Never go down. Then match RPM class, voltage, shaft diameter and length, and the physical depth of the motor body. A taller aftermarket motor sits the blade higher in the shroud and costs you airflow.

Is 1075 versus 1100 RPM a problem?

No. Both are 6-pole, nominal 1200. That 25 RPM is a rating convention, not a spec to worry about. An 825 RPM motor is 8-pole and IS a different motor.

Why do these fail so fast around Dallas?

Because they run 8 or 9 months a year with 100 to 110F air coming off the coil and sun on the cabinet, and bearings and winding insulation both age on heat. A weak run capacitor makes it worse, because the motor draws high amps and cooks. That is why we meter the capacitor before we sell anybody a motor.