42
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;
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
Compresso r
rated
frequenc e 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
