Package Unit: YCY_G
Re: Convert from ECM to PSC Blower Motor
This unit comes from the factory with a Variable Speed ECM blower motor and ICM fan speed control.
► In a non-warranty motor failure situation, it may be financially beneficial for the customer to convert to a standard PSC blower motor.
| Parts Required: | ||||||
| Unit Size | 024 | 030 | 036 | 042 | 048 | 060 |
| 230V Blower Motor | 1/3HP | 1/2HP | 1/2HP | 3/4HP | 3/4HP | 1HP |
| Capacitor | ||||||
| Relay | 90-340 | 90-340 | 90-340 | 90-340 | 90-340 | 90-340 |
| 1/4" Female Spade | 8 Blue | 8 Blue | 8 Blue | 8 Blue | 8 Blue | 8 Blue |
CONVERSION STEPS:
1. Turn Off Power
- Disconnect power from the unit by pulling the service disconnect or by turning the breaker off.
- Open the panel to access the control compartment.
- Use a multi-meter to confirm that power is off.
2. Disconnect & Remove ECM Motor
- Remove the unit side panel to access the blower motor.
- Remove the High Voltage and Low Voltage plugs from the ECM Blower Motor.
- Remove the blower housing from the unit.
- Install a new 230V blower motor of equal Horsepower (HP).
- Check and note the motor's rated amperage for testing in Step 6.
- Install a correct-size capacitor and connect to the Brown & Brown/White wires from the new motor.
- Re-install the blower housing in the unit.
3. Install Fan Relay
- Mount a new 90-340 24V Fan Relay near the ICM Board in the control cabinet.
4. Re-Wire Low Voltage
- Disconnect the 16-Pin Low Voltage plug from the ICM Board and discard.
- Cut the 41G(BR) wire connected to the ICM Board.
- Install a 1/4" female spade terminal on the cut end of the wire.
- Cut the 41F(BR) wire connected to the ICM Board.
- Install a 1/4" female spade terminal on the cut end of the wire.
- Connect both wires (41G & 41F) to one side of the new Fan Relay coil.
- Cut the 36D(BL) & 36B(BL) wires connected to the ICM Board.
- Install a 1/4" female spade terminal on the cut end of both wires.
- Connect both wires (36D & 36B) to the other side of the new Fan Relay coil.
- Disconnect and discard the 35F(RD) wire between the IGN Board "L2" terminal and the ICM Board.
- Cut the 44D(YL) wire connected to the ICM Board and attach it to "Y" on the IGN Board.
- Cut the 47A(BK) wire going into "G" on the ICM Board and attach it to "G" on the IGN Board.
- Remove the ICM Board.
5. Wire High Voltage to Motor
- Disconnect and discard the Red & Black wires from the OLD ECM motor at the Fan Terminal Block (FTBA).
- Connect the White wire from the NEW motor to the Fan Terminal Block (FTBA) with the 1B(RD) wire.
- Connect the Black wire from the NEW motor to Terminal 3 (N/O) of the new Fan Relay.
- Make a new connector wire (14 ga. min.) and install 1/4" female spade connectors on both ends. (use the Black wire from the old motor if necessary).
- Connect one end of the new connector wire to Terminal 1 (COM) of the new Fan Relay
- Connect the other end of the new connector wire to the Fan Terminal Block (FTBA) with the 2B(BK) wire.
6. Re-Apply Power & Check Motor
- Re-apply High Voltage power to the unit by re-inserting the disconnect plug or by turning the breaker on.
- Set the thermostat Fan switch to "On".
- Ensure that the fan starts and runs in the correct rotation.
- Disconnect Power & Reverse Rotation if necessary.
- Use an Amp Probe to confirm that the motor amperage is within operating specs (from Step 2).
- Switch the thermostat Fan switch back to "Auto".
- Set the thermostat to call for heat.
- Ensure that the furnace burners fire and that the blower motor delays on and off properly.
