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

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Vacuum pump
When the Purge Abnormal button lights on the Failure and Alarm screen, the vacuum pump needs
to be disassembled for inspection. Contact your local Johnson Controls Service Center. The entire
purge line must be inspected if the Abnormal Purge Freq. button on the same screen lights, or
if the vacuum level of the purge line does not reach the specified level during the vacuum pump
capacity check.
Table 44: Vacuum pump troubleshooting
Item Cause Countermeasure
1 Deterioration of vacuum pump oil Replace the vacuum pump oil.
2
Incorrect operation of purging line
switching when vacuum pump capacity was
checked.
See Purge Procedure on page . Confirm the valves are open or
closed.
3 Deterioration of vacuum pump belt
4 Leakage in purge pipe lines.
5
Solenoid valve or check valve in the purge
line is clogged.
Contact your local Johnson Controls Service Center.
Abnormal solution and refrigerant levels
Causes of abnormal levels of solution and refrigerant and countermeasures against them are
shown in the following table. If the level of the solution or refrigerant is abnormal, correct it
according to the following procedure.
Table 45: Abnormal solution and refrigerant levels
Section
Normal
condition
Abnormal
condition
Cause Countermeasure
Cooling water
temperature at inlet is
high.
Chilled water
temperature at outlet is
low.
Heat exchange tube is
dirty.
Purging is insufficient.
Refrigerant
overflow G101
Air leaks in absorption
chiller.
• Check if the cooling water supply
rate matches the specification.
(Check the flow meter, discharge
pressure of the cooling water
pump, current, and so on.) If the
flow rate is low, check the opening
ratio of the flow controller valve and
check the strainer for clogging.
• Check the capacity of the cooling
tower.
• See Purge procedure .
• Check the capacity of the vacuum
pump.
• Check the purge unit for trouble.
• Purge air from the absorption
chiller. If partial-load operation
continues for a long time, non
condensable gas tends to stay in
the absorber. In this case, purge
directly from the low pressure side
(absorber). See Purge procedure .
Refrigerant tank
G102
Automatic on/off
temperature switch is not
set correctly. The cooling
water inlet temperature
is low.
• Check set value of automatic on/off
temperature switch 23AS.
• Check the cooling water inlet
temperature.
Purging is insufficient. See Purge procedure .
Internal cycle control
valve is not set correctly.
Solution tank
G103
Solution is crystallized.
Contact your local Johnson Controls
Service Center.
173 YHAU-C Single Effect Steam-Fired Absorption Chiller