58
Installation and Maintenance
Service Manual
No.
Malfunction
Name
Display Method of Indoor Unit
A/C status
Possible Causes
Dual-8
Code
Display
Indicator Display (during
blinking, ON 0.5s and OFF
0.5s)
operation
Indicator
Cool
Indicator
Heating
Indicator
19
Decrease
frequency
due to
high air
discharge
F9
All loads operate normally, while
operation frequency for
compressor is decreased
Overload or temperature is too high;
Refrigerant is insufficient;
Malfunction of electric expansion valve (EKV)
20
Limit/
decrease
frequency
due to
antifreezing
FH
All loads operate normally, while
operation frequency for compressor is
decreased
Poor air-return in indoor unit or fan speed is too
low
21
Voltage for
DC bus-bar
is too high
PH
During cooling and drying
operation, compressor will stop
while indoor fan will operate;
During heating operation, the
complete unit will stop operation.
1. Measure the voltage of position L and N on
wiring board (XT), if the voltage is higher than
265VAC, turn on the unit after the supply voltage
is increased to the normal range.
2.If the AC input is normal, measure the voltage
of electrolytic capacitor C on control panel (AP1),
if its normal, theres malfunction for the circuit,
please replace the control panel (AP1)
22
Voltage of
DC bus-bar
is too low
PL
During cooling and drying
operation, compressor will stop
while indoor fan will operate;
During heating operation, the
complete unit will stop
1. Measure the voltage of position L and N on
wiring board (XT), if the voltage is higher than
150VAC,
turn on the unit after the supply voltage is
increased to the normal range.
2.If the AC input is normal, measure the voltage
of electrolytic capacitor C on control panel (AP1),
if its normal, theres malfunction for the circuit,
please replace the control panel (AP1)
23
Compressor
Min
frequence in
test state
P0
Showing during min. cooling or min. heating test
24
Compressor
rated
frequence in
test state
P1
Showing during nominal cooling or nominal
heating test
25
Compressor
maximum
frequence in
test state
P2
Showing during max. cooling or max. heating test
