38
Installation and Maintenance
Service Manual
2. Summary sheet for malfunction of ODU
No
Name of
Malfunction
Display of Outdoor Unit
AC Status
Possible Causes
Indicator has 3 kinds of
display status and they will
be displayed circularly every
5s
□ OFF ■ON
☆
Blink
D5
D6
D16
D30
1
High pressure
protection of system
□
☆
☆
☆
During cooling and drying
operation, except indoor
fan operates, all loads stop
operation. During heating
operation, all loads stop
operation.
1. Refrigerant is superabundant;;
2. Poor heat exchange (including filth blockage of
heat exchanger and bad radiating environment);
3. Ambient temperature is too high;
4. High pressure switch is damaged.
2
Freeze prevention
protection
■
□
■
□
During cooling and drying
operation, except indoor
fan operates, all loads stop
operation. During heating
operation, all loads stop
operation.
1. Poor air-return in indoor unit;
2. Fan speed is abnormal;
3. Evaporator is dirty;
4. Indoor tube temperature sensor is abnormal
3
High discharge
temperature
protection of
compressor
■
□
■
☆
During cooling and drying
operation, compressor and
outdoor fan stop while indoor
fan operates. During heating:
all loads stop operation.
Please refer to the malfunction analysis (discharge
protection, overload)
4
AC overcurrent
protection
□
■
☆
□
During cooling and drying
operation, compressor and
outdoor fan stop while indoor
fan operates. During heating:
all loads stop operation.
1. Supply voltage is unstable;
2. Supply voltage is too low and load is too high;
3. Current is too high due to overload
5
Current detection
malfunction of the
whole unit
□
■
☆
■
During cooling and drying
operation, compressor and
indoor fan operate. During
heating operation, all loads
stop operation.
The circuit on control board of outdoor unit has
malfunction. Replace the control board of outdoor
unit.
6
Communication
malfunction
between IDU and
ODU
□
□
□
☆
During cooling operation,
compressor stops while
indoor fan operates. During
heating: all loads stop
operation.
Refer to the malfunction analysis.
7
High temperature
resistant protection
■
□
■
■
During cooling operation,
compressor stops while
indoor fan operates. During
heating operation, all loads
stop operation.
Refer to the malfunction analysis (overload, high
temperature resistant).
8
Outdoor ambient
temperature sensor
is open/short
circuited
□
□
☆
■
During cooling and drying
operation, compressor stops
while indoor fan operates.
During heating operation, all
loads stop operation.
1.Outdoor ambient temperature sensor is poorly
connected (refer to the wiring diagram of indoor
unit);
2. Outdoor ambient temperature sensor is damaged
(please refer to the resistance table of temperature
sensor)
9
Outdoor condenser
temperature sensor
is open/short
circuited
□
□
☆
□
During cooling and drying
operation, compressor stops
while indoor fan operates.
During heating, all loads stop
operation.
1.Outdoor pipe temperature sensor is poorly
connected (refer to the wiring diagram of indoor
unit);
2. Outdoor pipe temperature sensor is damaged
(please refer to the resistance table of temperature
sensor)
10
Outdoor discharge
temperature sensor
is open/short
circuited
□
□
☆
☆
During cooling and drying
operation, compressor stops
after running for 3 minutes,
and indoor fan operates.
During heating: all loads stop
operation after running for 3
minutes.
1.Outdoor air discharge temperature sensor is
poorly connected (refer to the wiring diagram of
indoor unit);
2. Outdoor air discharge temperature sensor is
damaged (please refer to the resistance table of
temperature sensor)
