35
Troubleshooting and Diagnostics
A total of 17 failure input alarm switches, as well as 1 fault output alarm switch, are provided for
dual compressor system
S/N Input port Fault Description
Type Code
Central
Controller
Code
Troubleshooting
1
TH1
Return water temperature sensing
line in short/open circuit
A
SE
84
All peripherals are to be closed.
2
TH2
Outlet water temperature sensing
line in short/open circuit
A
SL
85
All peripherals are to be closed.
3
TH3
Discharge temperature 1 in short/
open circuit
A
Sd
82
All peripherals are to be closed.
4
TH4
Defrost temperature sensing line
1 in short/open circuit
A
S1
7F
All peripherals are to be closed.
5
TH5
Defrost temperature sensing line
2 in short/open circuit
A
S2
81
All peripherals are to be closed.
6
TH6
Discharge temperature short/open
circuit
A
S3
83
All peripherals are to be closed.
7
OVHT/HP2 Compressor 2 high voltage
pressure alarming
E
H2
65
Only compressor 2 is to be shut down.
8
FLOW
Inadequate water flow
D
FL
6D
All peripherals are to be closed.
9
OV-PUMP
Water pump overloaded
B
OP
6A
All peripherals are to be closed.
10
OV-FAN
Fan overloaded
B
OF
6B
All peripherals are to be closed.
11
OV-COMP1
Compressor 1 overloaded /
Compressor 1 middlum-pressure
alarming
C
78
78
Only compressor 1 is to be shut down.
12
OV-COMP2
Compressor 2 overloaded /
Compressor 2 middlum-pressure
alarming
E
78
78
Only compressor 2 is to be shut down.
13
HP1
Compressor 1 high voltage
pressure alarming
C
H1
64
Only compressor 1 is to be shut down.
14
LP1
Compressor 1 low voltage
pressure alarming
C
L1
66
Only compressor 1 is to be shut down.
15
FREZ/LP2 Compressor 2 low voltage
pressure alarming
E
L2
67
Only compressor 2 is to be shut down.
16
/ / /
Refrigerating outlet water
temperature is too low.
D
E3
8D
The compressor is to be shut down, while
the auxiliary heater of water pump is to work.
17
TH3
Discharge temperature 1 is too
high.
D
94
94
Only compressor 1 is to be shut down.
18
TH6
Discharge temperature 2 is too
high.
D
94
94
Only compressor 2 is to be shut down.
19
TH4
Coil 1 temperature is too high.
C
98
98
Only compressor 1 is to be shut down.
20
TH5
Coil 2 temperature is too high.
C
98
98
Only compressor 2 is to be shut down.
21
TH2
BPHE outlet water temperature is
too high.
C
90
90
All peripherals are to be closed.