JOHNSON CONTROLS
157
SECTION 8 – TROUBLESHOOTING
FORM 155.30-ICOM2.EN.UL
ISSUE DATE: 12/21/2018
8
TABLE 37 -
CHILLED WATER SUSPENSION
ITEM
CAUSE
COUNTERMEASURE
1
Chilled water pump has a
problem
Check the chilled water pump for a problem.
2
Chilled water flow rate is
low
Check to see if the chilled water flow rate is below the setpoint of the water
suspension switch. If it is low, check the flow controller, check the strainer for
clogging, and check the opening ratio of the flow control valve.
3
Pressure transfer pipe of
water suspension switch
is clogged
Contact your local Johnson Controls Service Office.
4
Water suspension switch
is broken
In the case of Chilled Water Suspension, the absorp-
tion chiller does not perform diluting operation but
stops immediately. If the absorption chiller is left as
is, the solution in it will crystallize in 4-5 hours. To
prevent this, dilute the solution according to "manual
refrigerant blowing and diluting method".
TABLE 38 -
ABNORMAL PUMP OPERATION
ITEM
CAUSE
COUNTERMEASURE
1
Bearings of the pump are
worn or clogged
Contact your local Johnson Controls Service Office.
2
Pump is damaged by
cavitation caused by low
liquid level
3
Thermal switch is not set
properly
4
Internal cycle control
valve is not set properly
5
Filter in the pump is
clogged
6
Solution is crystallized
7
Circuit breaker has
tripped
If the chiller has a pump problem, it does not perform
the diluting operation but stops immediately. If left as
is, the solution will crystallize in 4-5 hours. To prevent
this, contact your local Johnson Controls Service Of-
fice immediately.
TABLE 39 -
CHILLED WATER TIME OUT OR COOLING WATER TIME OUT
ITEM
CAUSE
COUNTERMEASURE
1
Pump abnormal
Check the water pump.
2
Insufficient water flow
Check the water line and check water flow.
3
Water suspension relay
abnormal
Check the water suspension relay. Check to see if the pipe is clogged or not.
4
Water pump interlock
abnormal
Check the water pump.
