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JOHNSON CONTROLS
23
FORM 160.76-O1
ISSUE DATE: 05/22/2019
6
SECTION 6 - MAINTENANCE
RENEWAL PARTS
Please order all replacement parts at
LD28095
FIGURE 10 -
PARTS NAVIGATOR
CHECKING SYSTEM FOR LEAKS
Leak Testing During Operation
The refrigerant side of the system is carefully pressure
tested and evacuated at the factory.
After the system has been charged, the system should
be carefully leak tested with a compatible leak detector
to be sure that all joints are tight.
If any leaks are indicated, they must be repaired im-
mediately. Usually, leaks can be stopped by tighten-
ing flare nuts or flange bolts. However, for any major
repair, the refrigerant charge must be removed. (See
Handling Refrigerant For Dismantling And Repairs
)
CONDUCTING PRESSURE TEST
With the refrigerant charge removed and all known
leaks repaired, the system should be charged with a
small amount of refrigerant mixed with dry nitrogen so
that electronic leak detector can be used to detect any
leaks too small to be found by the soap test.
To test with refrigerant, proceed as follows:
1. With no pressure in the system, charge refrigerant
gas into the system through the charging valve to
a pressure of 2 psig (14 kPa).
2. Build up the system pressure with dry nitrogen to
approximately 75 psig to 100 psig (517 kPa to 690
kPa). To be sure that the concentration of refriger-
ant has reached all parts of the system, slightly
open the oil charging valve and test for the pres-
ence of refrigerant with a leak detector.
EVACUATION AND DEHYDRATION OF UNIT
FIGURE 11 -
EVACUATION OF CHILLER
27385A(D)
LD00949
STOP VALVE
CHARGING VALVE
VACUUM PUMP
WET BULB TEMPERATURE
INDICATOR OR VACUUM GAUGE