Johnson Controls YVAHP072B31S, Service Manual

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Service Manual
3-123
TROUBLESHOOTING
If there is no abnormality (Alarm Code) indicated on the wired controller, and normal operation is not
available, take necessary action according to the following procedures.
Other
Abnormalities
Abnormalities of Devices
3.2.3 Abnormalities of Devices
*1): For CIW01, refer to Section 3.1.4 (3).
*2): For CIW01, refer to Section 3.1.4 (2).
*3): Even if controllers are normal, the compressor does not operate under the following conditions.
* Indoor Air Temp. is lower than 69.8°F (21°C) or Outdoor Air Temp. is lower than 23°F (-5°C) during cooling
operation.
* Indoor Air Temp. is higher than 86°F (30°C) or Outdoor Air Temp. is higher than 73.4°F (23°C) during heating
operation.
* When a cooling (or heating) operation signal is given to the outdoor unit and a different operation signal is given
to indoor units.
* When demand signal or emergency stop signal is given to outdoor unit.
Cause Check Item
Action
(Turn OFF Main Switch)
Event
Measure coil
resistance with tester.
Replace indoor unit
fan motor.
Failure of
Indoor Unit
Fan Motor
Disconnected
Coil
"RUN" Indicator
and LCD are ON.
However, the
system does
not operate.
(example)
Indoor/outdoor
fans or
compressor
do not operate.
The Comp.
does not Stop
or Start even
if the temperature
setpoint
on the LCD is
Changed *3)
Measure insulation
resistance. Burned-Out
Coil
Measure coil
resistance with tester.
Replace outdoor unit
fan motor.
Failure of
Outdoor Unit
Fan Motor
Disconnected
Coil
Measure insulation
resistance. Burned-Out
Coil
Check connection.
Failure of
One of PCBs
Disconnected
Wire to PCB
Check PCB in
self-checking mode *1).
Correctly connect
wires.
Replace PCB if faulty.
Check it in
self-checking mode *1).
Check it in
Check Mode *2).
Failure of
PCB
Replace or correctly
connect wires
if abnormal.
Failure of
Air Inlet
Thermistor
Failure of
Thermistor
Disconnection
of Thermistor
Check whether magnetic
switch is activated
correctly.
Replace magnetic
switch.
Replace PCB if faulty.
Failure of
Magnetic
Switch for
Comp.
Contact
Failure
Measure resistance
between wires.
Replace compressor.
Failure of Comp. Motor
Check for abnormal
sound from comp.
Failure of Comp.
Abnormality of
Wired Zone Controller Cord
Check it in Run Test.
Failure of Indoor Unit PCB
for
outdoor unit,
indoor unit,
wired zone
controller
Check it in Test Run.
Abnormality of
Wired Controller Cord