York YHAU-CW - Chilled Water Overcooling or Refrigerant Overcooled

JOHNSON CONTROLS
158
FORM 155.31-ICOM2.EN.UL
ISSUE DATE: 12/21/2018
SECTION 8 – TROUBLESHOOTING
TABLE 35 - TROUBLESHOOTING THE HIGH
TEMPERATURE GENERATOR
ITEM CAUSE COUNTERMEASURE
1
Cooling water is Insufcient
or suspended.
• See if the cooling water supply rate conforms to the specication. Check the ow
meter, discharge pressure of the cooling water pump, current,and other applicable
pumps or pressures.
• If the ow rate is insufcient, check the opening ratio of the ow 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 capacity of the vacuum pump.
• Check the purge unit.
• Purge air from the chiller (See SECTION 7 – MAINTENANCE).
• If partial load operation is continued for a long period, non-condensable gas tends
to stay in the absorber. In this case, purge directly from the low pressure side
(according to instructions in SECTION 7 – MAINTENANCE).
4
Heat exchange tube is
dirty (chilled water, cooling
water).
Contact your local Johnson Controls Service Ofce.
5 Solution is crystallized.
6 Corrosion inhibitor is worn.
7
Air leaks in absorption
chiller.
TABLE 36 - CHILLED WATER OVERCOOLING OR
REFRIGERANT OVERCOOLED
ITEM CAUSE COUNTERMEASURE
1
Chilled water ow rate
lowers or changes sharply.
See if the chilled water ow rate changes sharply (particularly in the case
of variable ow rate specication). If it changes sharply, apply a limit of the
change rate to the chilled water ow control or take another measure.
2
Cooling water temperature
at inlet changes sharply.
• See if the cooling water temperature at inlet changes sharply. Checking the
start and stop of the fan).
• If the chiller refrigerant temperature is low, the chiller stops immediately but
does not perform the diluting operation. If left as it is, the solution may be
crystallized in 4-5 hours. To prevent this, dilute the solution according to the
procedure shown in Manual Refrigerant Blow Down and Diluting Method on
page 137.
3 Load lowers sharply. See if the load changes sharply.
4
Refrigerant is dirty
(contains solution).
See if the refrigerant rening operation has been performed. For the refrigerant
rening method, see NOTE: Do not loosen the bolts around the ange or
remove the disk from the holder. If the disk is removed for any reason, it must
be replaced with a new one! on page 30
5
Heat exchange tube is
dirty (Chilled water).
Contact your local Johnson Controls Service Ofce.
6
Temperature controller or
safety switch is broken.