Johnson Controls York YHAU-C, Installation, Operation And Maintenance Manual

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Table 37: Abnormal pump operation
Item Cause Countermeasure
1 Bearings of the pump are worn or clogged.
2
Pump is damaged by cavitation caused by
low liquid level.
3 Thermal switch is not set correctly.
4
Internal cycle control valve is not set
correctly.
5 Filter in the pump is clogged.
6 Solution is crystallized.
7 Circuit breaker has tripped.
Contact your local Johnson Controls Service Office.
Table 38: 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.
Table 39: Pump interlocks
Item Cause Countermeasure
1 Water pump interlock was not established Check the water pump interlock.
Table 40: Low cooling water inlet temperature
Item Cause Countermeasure
1
Cooling water inlet temperature control
system is abnormal
Check the cooling water inlet temperature control system. If
this problem occurs, the absorption chiller performs the diluting
operation automatically and then stops.
Go to the Control Center. Confirm that the diluting operation is
performed.
If the dilution operation did not run, dilute the solution according to
the procedure shown in Manual Refrigerant Blowdown and Diluting
Method on page .
If these problems occur, the absorption chiller performs the diluting operation automatically and
then stops. Go to the Control Center immediately. Confirm that the dilution operation ran. If it did
not, dilute the solution according to the procedure shown in Manual Refrigerant Blowdown and
Diluting Method on page .
Table 41: Abnormal control sensor
Item Cause Countermeasure
1 Contact failure Tighten terminal in control panel
2 Sensor abnormal or disconnected
3 Inductive noise
Contact your local Johnson Controls Service Office.
Table 42: CPU abnormal
Item Cause Countermeasure
1 Control board malfunction Contact your local Johnson Controls Service Office.
171 YHAU-C Single Effect Steam-Fired Absorption Chiller