Table 39: Troubleshooting the high temperature generator
Item
Cause
Countermeasure
1
Cooling water is insufficient or
suspended.
•
See if the cooling water supply rate conforms to the specification. Check
the flow meter, discharge pressure of the cooling water pump, current, and
other applicable meters and gauges.
•
If the flow rate is insufficient, check the opening ratio of the flow controller
valve and check the strainer for clogging.
2
Cooling water temperature at
inlet is high.
Check the capacity of the cooling tower.
3
Non-condensable gas stays in
the machine.
•
Check the purge unit.
•
Purge air from the chiller-heater. See
•
If partial load operation continues for a long period, non-condensable gas
tends to stay in the absorber. In this case, purge directly from the absorber.
Use the instructions shown in
4
Heat exchange tube is dirty
(chilled/hot water, cooling
water).
5
Solution is crystallized.
6
Corrosion inhibitor is worn.
7
Air leaks in absorption chiller-
heater.
Contact your local Johnson Controls Service Office.
Table 40: Refrigerant overcooling relay
Item
Cause
Countermeasure
1
Chilled/hot water flow
rate lowers or changes
sharply.
•
See if the chilled/hot water flow rate changes sharply (particularly in the case of
variable flow rate specification).
•
If it changes sharply, apply a limit of the change rate to the chilled/hot flow
control or take another measure.
2
Cooling water
temperature at inlet
changes sharply.
•
See if the cooling water temperature at inlet changes sharply (by checking start
and stop of the fan).
•
If the chiller-heater refrigerant temperature is low, the chiller-heater stops
immediately but does not perform the diluting operation. If left in the current
state, the solution can crystallize in 4-5 hours. To prevent this, dilute the solution
according to the information shown in
Manual refrigerant blow down and
.
Note:
The time required for refinement of the refrigerant depends on the
current load condition. Constantly check the liquid level in the refrigerant tank
while the refrigerant is being refined. If the refrigerant liquid level appears i the
level gauge of the refrigerant tank, close the valve immediately and completely.
3
Load lowers sharply.
Check if the load changes sharply.
4
Refrigerant is dirty
(contains solution).
Check if the refrigerant refining operation has been performed. For the refrigerant
refining method, see Refrigerant Refining Method on page .
5
Heat exchange tube is
dirty (Chilled/hot water).
6
Temperature controller
or safety switch is
broken.
Contact your local Johnson Controls Service Office.
Model YHAU-CGN/H-CXR(M)Double Effect Direct Fired Small Absorption Chiller-Heater
174
