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SERVICING
Motor
Connector
(3-pin)
Winding Test
Checking EEM Motors
The EEM motor is a one piece, fully encapsulated, 3 phase
brushless DC (single phase AC input) motor with ball
bearing construction. The EEM motor features an integral
control module.
NOTE: The GE TECMate will not currently operate the
EEM motor.
1. Using a voltmeter, check for 230 volts to the motor
connections L and N. If 230 volts is present, proceed
to step 2. If 230 volts is not present, check the line
voltage circuit to the motor.
2. Using a voltmeter, check for 24 volts from terminal C
to either terminal 1, 2, 3, 4, or 5, depending on which
tap is being used, at the motor. If voltage present,
proceed to step 3. If no voltage, check 24 volt circuit
to motor.
3. If voltage was present in steps 1 and 2, the motor has
failed and will need to be replaced.
NOTE: When replacing motor, ensure the belly band is
between the vents on the motor and the wiring has the
proper drip loop to prevent condensate from entering
the motor.
Motor OK when
R > 100k ohm
(3-pin)
High Voltage
Connections
C L G N
1 2 3 4 5
Low Voltage Connections
EEM Motor Connections
Checking ECM Motors
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 technicians are intimated by the
ECM motor; however, these fears are unfounded. GE/
Regal Beloit 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.
4. Check the control board.
5. If line voltage is present, reinsert the 5-pin connector
and remove the 16-pin connector.
6. Check for signal (24 volts) at the transformer.
7. Check for signal (24 volts) from the thermostat to the
"G" terminal at the 16-pin connector.
3/16"
1/4"
WARNING
19
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