Replace the Fan Motor / Motor Capacitor

Replace the Motor Run Capacitor and/or Motor

Low RPM on a condenser fan can be hard to spot.  If the fan is running, you would have skipped over checking the condenser fan motor run capacitor.  It will be important to verify that the existing run capacitor is the correct run capacitor for the motor and then verify the capacitor is within 10% of it’s rated MFD.

Reduced air flow across a condenser will decrease Btu output, and increase operating costs, it may also cause air cooled condenser fan motors to overheat and fail.  Run a Total Performance Diagnostic to quantify the extent of capacity and efficiency loss.

Three popular methods of checking run capacitors … (1) STATIC TEST > Disconnect all wiring from the capacitor and reading MFD across the terminals with a properly equipped meter. … (2) LOAD TEST > Read the amperage of the common and run windings together inside the amp meter clamp. Then read the amperage of the start winding. If the readings are within .5 amps the run capacitor is ok … (3) CALCULATED LOAD TEST > Record the voltage across the capacitor leads. Record the motor amp draw on the common leg.  Actual MFD capacity = 2652 x start winding amps / run cap voltage

Home Page          Back