Bard CH5S1, CH4S1, CH3S1 Troubleshooting GE ECM Motors Contd, Replacing ECM Control Module

Troubleshooting GE ECM™ Motors (Cont'd.)

Replacing ECM Control Module

To replace the control module for the GE variable-speed indoor blower motor you need to take the following steps:

1.You MUST have the correct replacement module. The controls are factory programmed for specific operating modes. Even though they look alike, different modules may have completely different functionality.

Using the wrong control module voids all product warranties and may produce unexpected results.

2.Begin by removing AC power from the unit being serviced. do not work on the motor with ac power applied. To avoid electric shock from the motor’s capacitors, disconnect power and wait at least 5 minutes before opening motor.

3.It is not necessary to remove the motor from the blower assembly, nor the blower assembly from the unit. Unplug the two cable connectors to the motor control assembly. There are latches on each connector. do not pull on the wires. The plugs remove easily when properly released.

4.Locate the screws that retain to the motor control bracket to the sheet metal of the unit and remove them. Remove two (2) nuts that retain the control to the bracket and then remove two (2) nuts that retain sheet metal motor control end plate. Refer to Figure 14.

5.Disconnect the three (3) wires interior of the motor control by using your thumb and forefinger squeezing the latch tab and the opposite side of the connector plug, gently pulling the connector. DO NOT PULL ON THE WIRES, GRIP THE PLUG ONLY. Refer to Figure 14.

6.The control module is now completely detached from the motor. Verify with a standard ohmmeter that the resistance from each motor lead (in the motor plug just removed) to the motor shell is >100K ohms. Refer to Figure 15. (Measure to unpainted motor end plate.) If any motor lead fails this test, do not proceed to install the control module. the motor is defective and must be replaced. Installing the new control module will cause it to fail also.

7.Verify that the replacement control is correct for your application. Refer to the manufacturer’s authorized replacement list. Using the wrong control will result in improper or no blower operation. Orient the control module so that the 3-wire motor plug can be inserted into the socket in the control. Carefully insert the plug and press it into the socket until it latches. a slight click will be heard when properly inserted.

8.Reverse the steps #5, 4, 3 to reconnect the motor control to the motor wires, securing the motor control cover plate, mounting the control to the bracket, and mounting the motor control bracket back into the unit. make sure the orientation you select for replacing the control assures the control's cable connectors will be located downward

in the application so that water cannot run down the cables and into the control. do not overtighten the bolts.

9.Plug the 16-pin control plug into the motor. The plug is keyed. Make sure the connector is properly seated and latched.

10.Plug the 5-pin power connector into the motor. Even though the plug is keyed, observe the proper orientation. do not force the connector. It plugs in very easily when properly oriented. reversing this plug will cause immediate fAILure of the control module.

11.Final installation check. Make sure the motor is installed as follows: a. Motor connectors should be oriented between the 4 o’clock

and 8 o’clock positions when the control is positioned in its final location and orientation.

b. Add a drip loop to the cables so that water cannot enter the motor by draining down the cables. Refer to Figure 16.

The installation is now complete. Reapply the AC power to the HVAC equipment and verify that the new motor control module is working properly. Follow the manufacturer’s procedures for disposition of the old control module.

	Figure 14			Figure 15
	Control Disassembly			Winding Test
			Motor Connector
Only remove	From Motor		(3-pin)
Hex Head Bolts	Push until
	Latch Seats
	Over Ramp
		Circuit
		Board
		Motor
ECM 2.0
				Motor OK when
Note:				R > 100k ohm
Use the shorter
bolts and
alignment pin
				Figure 16
supplied when
replacing an				Drip Loop
ECM 2.0		Motor Connector
control.			Back of	Connector Orientation
		(3-pin)
ECM			Control	Between 4 and 8 o'clock
2.3/2.5		Control Connector
		(16-pin)
		Power Connector
		(5-pin)
				Drip Loop

Manual	2100-455M
Page	28 of 28