7
7
.
.
T
T
R
R
O
O
U
U
B
B
L
L
E
E
S
S
H
H
O
O
O
O
T
T
I
I
N
N
G
G
ON/OFF UNITARY AIR CONDITIONER TECHNICAL& SERVICE MANUAL V5.0
111
Fault
code
Fault Description
Possible Reason of Abnormality
How to Deal With
6
Communication between
driver board and control
board fault
1,Communication wire connect not well;
2,Driver board fault;
3,Control board fault;
1, Check compressor wire connect.
2,Change the driver board;
3,Change the control board ;
7
AC voltage,overload
voltage
1,Supply voltage input too high or too low;
2,Driver board fault;
1,Check power supply;
2,Change the driver board;
8
DC voltage,overload
voltage
1,Supply voltage input too high ;
2,Driver board fault;
1,Check power supply;
2,Change the driver board;
9 AC voltage imbalance
Driver board fault;
Change the driver board;
10
The current detection
circuit fault
Bad driver board components;
Change the driver board
11
AC voltage supply in
1,Power supply abnormal, power
frequency out of range;
2,Driver board fault;
1,Check the system;
2,Change the driver board;
12
Products of single-phase
PFC over-current, FO
output low level
1,System overload, current too large;
2,Driver board fault;
3,PFC fault.
1,Check the system;
2,Change the driver board;
3,Change PFC.
13
Inverter over current
(3-phase power supply air
conditioners)
1,System overload, current too large;
2,Driver board fault;
3，Compressor oil shortage, serious wear
of crankshaft;
4,The compressor insulation fault.
1,Check the system;
2,Change the driver board;
3, Change the Compressor;
4, Change the Compressor.
14
Inverter over current
1,System overload, current too large;
2,Driver board fault;
3,Compressor oil shortage,serious wear of
crankshaft;
4,The compressor insulation fault.
1,Check the system;
2,Change the driver board;
3, Change the Compressor;
4, Change the Compressor.
15
PFC over
current(single-phase
air-conditioner)
1,System overload, current too large;
2,Driver board fault;
3,PFC fault..
1,Check the system;
2,Change the driver board;
3,Change PFC.
16
Phase imbalance or
phase lacks or the
instantaneous power
failure (only for 3-phase
power supply air
conditioners)
1,3-Phase voltage imbalance;
2,The 3-phase power supply phase lost;
3,Power supply wiring wrong;
4,Driver board fault.
1,Check the power supply;
2,Check the power supply;
3,Check the power supply wiring connect;
4,Change the driver board.
17
The instantaneous power
failure detection
1,The power supply is not stable ;
2.The instantaneous power failure ;
3,Driver board fault;
1,Check the power supply.
2,Not fault.
3,Change the driver board;
18
Low DC voltage 200V
1,Voltage input too low ;
2,Driver board fault.
1,Check the power supply.
2,Change the driver board.
Ii： Driver board fault codes trouble shooting
（ONLY FOR 20K&16K DUAL TYPES）,details see sheet6.
2-seconds long LED flash on/off in means number 5，1 -second short LED flash on/off means number 1.