47
Service Manual
Installation and Maintenance
NO.
Malfunction
Name
Display Method of Indoor Unit
Display Method of Outdoor
Unit
A/C status
Possible Causes
Dual-8
Code
Display
Indicator Display (during
blinking, ON 0.5s and OFF
0.5s)
Indicator has 3 kinds of
display status and during
blinking, ON 0.5s and OFF
0.5s
Operation
Indicator
Cool
Indicator
Heating
Indicator
Yellow
Indicator
Red
Indicator
Green
Indicator
44
Malfunction of
phase current
detection
circuit for
compressor
U1
OFF 3S
and blink
13 times
During cooling and drying
operation, compressor will stop
while indoor fan will operate;
During heating operation, the
complete unit will stop
Replace outdoor control panel AP1
45
Malfunction of
voltage
dropping for
DC bus-bar
U3
OFF 3S
and blink
20 times
During cooling and drying
operation, compressor will stop
while indoor fan will operate;
During heating operation, the
complete unit will stop
Supply voltage is unstable
46
Malfunction
of complete
units current
detection
U5
OFF 3S
and blink
13 times
During cooling and drying
operation, the compressor will
stop while indoor fan will
operate;
During heating operating,
the complete unit will stop
operation.
Theres circuit malfunction on
outdoor units control panel AP1,
please replace the outdoor units
control panel AP1.
47
The four-way
valve is
abnormal
U7
OFF 3S
and blink
20 times
If this malfunction occurs
during
heating operation, the complete
unit will stop operation.
1.Supply voltage is lower than
AC175V;
2.Wiring terminal 4V is loosened or
broken;
3.4V is damaged, please replace
4V.
48
Zero-
crossing
malfunction of
outdoor unit
U9
OFF 3S
and blink
18 times
During cooling operation,
compressor will stop while
indoor fan will operate; during
heating,the complete unit will
stop operation.
Replace outdoor control panel AP1
49
Frequency
limiting
(power)
OFF 3S
and blink
13 times
50
Compressor
is open-
circuited
OFF 3S
and blink
once
51
The
temperature
for turning
on the unit is
reached
OFF 3S
and blink
8 times
52
Frequency
limiting
(module
temperature)
OFF 3S
and blink
11 times
