YCY_G - Convert from ECM to PSC Blower Motor

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.

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.