Features of the Fasco Condenser Fan Motor
Has an all angle mount
Extended tie rods that are on both ends
Flat end bells on both ends
4-drilled and tapped holes
How-To Wire Condenser Fan Motors: 3-Wire & 4-Wire Configurations
Fasco condenser fan motors contain three or four wires and can be replaced using either a three or four-wire set-up when using a single-run capacitor or in other cases, a dual-run capacitor.
A review of the components:
Outdoor Fasco condenser units use a switch that is known as a contactor. The switch is usually controlled by the thermostat. It closes to complete an electric circuit every time the electricity needs to be supplied to your Fasco condenser fan motor and compressor. Essentially, the contactor acts as a ‘gatekeeper’ that contains two legs of about 115 volt electric supply that needs to flow through, so the system can function properly.
Fasco condenser units use a component that is known as a run capacitor. These capacitors allow the Fasco condenser fan motors and compressors to function more smoothly, and are measured in microfarads. The dual-run capacitors are used for both the Fasco condenser fan motor and the compressor. Your contactor needs to be wired correctly just like the capacitor. Correct wiring ensures proper functioning.
Using a dual run capacitor:
While using a dual-run Fasco capacitor, you are required to use three or four leads that are coming off the new Fasco condenser fan motor.
In this type of capacitor, the black lead should be wired in the same position that the previous Fasco condenser fan motor was wired to. This will most likely be back to your contactor. Then wire the white lead to the same position that the previous white lead condenser motor was wired to. This will be the “C” also known as the common terminal on your dual run capacitor. For the brown lead, wire it to the same position as the old one. The process should be similar to the white and black leads. The brown lead should be on the “F”, also known as the fan terminal on the dual run capacitor. For this particular setup, you will not be required to use the brown lead with the white tracer. Tie the connections off using a wire nut or with electrical tape.
Note, however, you will require a jumper between the “C” terminal that is on the capacitor and one leg that is on the contactor.
Using a single run capacitor with a four-wire setup:
If the Fasco condenser fan motor has a single-run capacitor, the wiring setup is different. Wire the black lead where the previous one was on your Fasco condenser fan motor.
This may be back to your contactor. You will then wire the white lead to the other leg of the contactor. Then, wire the brown lead onto one set of the terminals that are available on the new capacitor. With the brown lead still, wire it with the white tracer onto the other side of the terminals.
Using a single run capacitor with a three-wire setup:
If the Fasco single run capacitor is newly purchased, and the Fasco condenser that you are using only contains three leads coming from it, this is the wiring setup: Wire the black lead back to the place where it was originally wired in the previous connection. The white wire should then be wired to the set of terminals that are on the new capacitor. Wire the jumper from this set of terminals back to the other leg that is on your contactor. The brown lead should be wired to the opposite set of terminals that are on the new Fasco run capacitor.
Conclusion:
Wiring a new Fasco condenser fan motor and a run capacitor can prove to be quite tricky especially if the project is undertaken as a DIY and it is one that you have not done before. On that note, safety is always one of the things that must be kept as a priority at all times. Make sure that the electrical supply to the Fasco condenser unit is disconnected before you begin. To further ensure that it is safe to work, use a multimeter to confirm that there is complete disconnection.
Before removing the Fasco condenser fan motor or run capacitor, make sure that you document the location of each existing wire connection clearly and in detail. Take pictures of the connections for reference during installation. Contact an HVAC contractor if you need any help.