52
SERVICING
S-9 CHECKING HIGH AND LOW VOLTAGE TO
ECM MOTOR
WARNING
HIGH VOLTAGE
Disconnect ALL power before servicing or installing
this unit. Multiple power sources may be present.
Failure to do so may cause property damage, personal
injury or death.
3. Measure voltage between black and brown motor leads.
This should measure 208/230 volts depending on your
power supply.
4. If voltage is present proceed to check fan relay contacts
and voltage.
Checking FAN Relay Contacts - ECM Fan Motor
1. Disconnect fan motor harness from plug on the UC board.
2. Energize the system in low stage and check voltage:
•
Pin 5(Blue wire) to Pin 3(Yellow wire) = 24VAC
3. Energize the system in high stage and check voltage:
•
Pin 5(Blue wire) to Pin 3(Yellow wire) = 24VAC
•
Pin 5(Blue wire) to Pin 1(White wire) = 24 VAC.
4. If voltage is present at these pins plug harness into plug
on PC board and check voltages at motor to test for
broken wires.
5. If all voltages are present motor is defective and needs to
be replaced.
Checking Relay Contacts - PSC Fan Motor
WARNING
HIGH VOLTAGE
Disconnect ALL power before servicing or installing
this unit. Multiple power sources may be present.
Failure to do so may cause property damage, personal
injury or death.
1. Disconnect the motor leads from 6-circuit fan motor wire
harness.
2. Connect a voltmeter between circuit 3 and circuits 2 (low
speed) or 1 (high speed).
NOTE:
Circuit 3 is connected directly to L2.
3. Energize the system at low or high stage.
WARNING
Line Voltage now present.
4. The measured voltage between circuit 3 and circuits 2
or 1 should be approximately 0VAC, which indicates the
relay contacts are closed. A voltage measurement of
approximately 115VAC indicates the relay is open. Replace
the control if the relay checks open when it should be
closed. See notes and cautions below.
NOTE:
Ensure any ON delays have expired before making voltage
measurements
CAUTION:
Prolonged operation with the condenser fan motor
disconnected will cause the high pressure switch to trip.
S-10A Copeland Comfort Alert™ -
Unitary (UC) Control Diagnostics
Applies to DX16TC, DX18TC, DZ16TC, DZ18TC models
WARNING
HIGH VOLTAGE
Disconnect ALL power before servicing or installing
this unit. Multiple power sources may be present.
Failure to do so may cause property damage, personal
injury or death.
The Copeland Comfort Alert™ diagnostics are fully integrated
into the unitary (UC) control. The UC control and integrated
Comfort Alert™ diagnostics provide around-the-clock monitoring
for common electrical problems, compressor defects and broad
system faults. If a problem is detected, LED indicators flash the
proper alert codes to help you quickly pinpoint the problem.
The diagnostic tables on following pages provide detailed
information regarding the system symptoms, indicators (LED
and thermostat), potential problem(s), and corrective actions.
The diagnostic information applies to systems wired as 24VAC
traditional (legacy) systems and systems wired as communicating
systems with the CTK0* communicating thermostat.
