4 Troubleshooting
Alarm indication
SMGB0120 rev.0 - 11/2017
93
4
4.5
Alarm indication
In case of occurrence of sensor abnormalities while the chiller unit is stopped, or of abnormalities that would not trigger
an alarm stop, a warning is output to the outside and warning display is conducted. The mark
is shown on the LCD
Screen during warning external output.
The content of warning is shown in the table below.
Caution is
illuminated
Spanner mark
Yellow during
occurrence of warning
Warning
contents display
Warning icon is
shown
Warning indication
Contents of warning
Notes
Freeze prevention
Water temperature is 1ºC or below
When compressor is stopped while
the chiller unit is in operation *1
Inlet water temperature thermistor
abnormality (CN4)
Disconnection or short-circuit of the inlet water
temperature thermistor
When the chiller unit is stopped *2
Outlet water temperature thermistor
abnormality (CN5)
Disconnection or short-circuit of the outlet water
temperature thermistor
When the chiller unit is stopped *2
Cooler inlet thermistor abnormality (CN29) Disconnection or short-circuit of the cooler inlet
(evaporating temperature) thermistor
When the chiller unit is stopped *2
Discharge gas thermistor abnormality
(CN26)
Disconnection or short-circuit of the discharge gas
thermistor
When the chiller unit is stopped *2
Liquid temp thermistor abnormality (CN24) Disconnection or short-circuit of the liquid
temperature thermistor
When the chiller unit is stopped *2
Outlet rear side thermistor abnormality
(CN25)
Disconnection or short-circuit of the (rear side)
outlet water temperature thermistor
When the chiller unit is stopped *2
Suction gas thermistor abnormality (CN27) Disconnection or short-circuit of the suction gas
thermistor
When the chiller unit is stopped *2
Discharge pressure sensor abnormality
(CN31)
Disconnection or short-circuit of the high pressure
sensor
When the chiller unit is stopped *2
Suction pressure sensor abnormality
(CN32)
Disconnection or short-circuit of the low pressure
sensor
When the chiller unit is stopped *2
Water supply header thermistor
abnormality (CN13)
Disconnection or short-circuit of the water supply
header thermistor
When using the function to control
the number of units / When system
is stopped (in 2-pump system I or II)
Water return header thermistor
abnormality (CN14)
Disconnection or short-circuit of the water return
header thermistor
CPU-I/O Transmission
Transmission abnormality between CPU-I/O PCBs When the chiller unit is stopped *2
COMP Run/Stop Frequency
Frequency of compressor run/stop higher than 6
times/hour
Transmission of Control of Master/Slave
group
Transmission abnormality between Unit No.1 and
Unit No.2 and the following
When using the function to control
the number of units / When system
is stopped *2
Incorrect Setting of Control of Master/
Slave group
Incorrect setting of DIP Switch / Rotary Switch
When using the function to control
the number of units / When system
is stopped *2
Insufficient number of operable units
Number of operable chiller units < Setting value of
minimum number of operating units
When using the function to control
the number of units
Overhaul Period
Operating time period of compressor higher than
40000 hours *3
Warning mark is not displayed.
Spanner mark is displayed
I/O internal transmission
CO072 (I/O PCB) Abnormality
When chiller unit is stopped *2
*1. It becomes an alarm when compressor is in operation.
*2. It becomes an alarm when the chiller unit is put to operation while in alarm output status.
*3. The spanner mark disappears when operating time period of the compressor is changed to less than 40000 hours. Warning display is
automatically released when the abnormal condition is cleared.
