Goodman Mfg R-410A manual Checking Motors, APH15 M Series Only

SERVICING

S-16 CHECKING MOTORS

S-16B CHECKING FAN AND BLOWER MOTOR (ECM MOTORS)

APH15 M Series Only

An ECM is an Electronically Commutated Motor which offers many significant advantages over PSC motors. The ECM has near zero rotor loss, synchronous machine operation, variable speed, low noise, and programmable air flow. Because of the sophisticated electronics within the ECM motor, some techni- cians are intimated by the ECM motor; however, these fears are unfounded. GE offers two ECM motor testers, and with a VOM meter, one can easily perform basic troubleshooting on ECM motors. An ECM motor requires power (line voltage) and a signal (24 volts) to operate. The ECM motor stator contains permanent magnet. As a result, the shaft feels "rough" when turned by hand. This is a characteristic of the motor, not an indication of defective bearings.

LINE VOLTAGE NOW PRESENT.

1.Disconnect the 5-pin connector from the motor.

2.Using a volt meter, check for line voltage at terminals #4 & #5 at the power connector. If no voltage is present:

3.Check the unit for incoming power See section S-1.

4.If line voltage is present, reinsert the 5-pin connector and remove the 16-pin connector.

5.Check for signal (24 volts) at the transformer.

6.Check for signal (24 volts) from the thermostat to the "G" terminal at the 16-pin connector.

7.Using an ohmmeter, check for continuity from the #1 & #3 (common pins) to the transformer neutral or "C" thermostat terminal. If you do not have continuity, the motor may func- tion erratically. Trace the common circuits, locate and re- pair the open neutral.

8.Set the thermostat to "Fan-On". Using a voltmeter, check for 24 volts between pin # 15 (G) and common.

9.Disconnect power to compressor. Set thermostat to call for cooling. Using a voltmeter, check for 24 volts at pin # 6 and/or #14.

10.Set the thermostat to a call for heating. Using a voltmeter, check for 24 volts at pin #2 and/or #11.

1}Lines 1 and 2 will be connected

2for 12OVAC Power Connector applications only

3Gnd

4AC Line Connection

5AC Line Connection

	OUT -						OUT +
			8	16
ADJUST +/-
			7			15	G (FAN)
		Y1	6	14			Y/Y2
5			13	EM Ht/W2
					COOL
							24 Vac (R)
			4		12
	DELAY
			3	11			HEAT
COMMON2
		W/W1					BK/PWM (SPEED)
			2		10
COMMON1							O (REV VALVE)
			1	9

16-PIN ECM HARNESS CONNECTOR

If you do not read voltage and continuity as described, the problem is in the control or interface board, but not the motor. If you register voltage as described , the ECM power head is defective and must be replaced.

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