Check Chiller Tightness; Refrigerant Tracer; Leak Test Chiller - Carrier AquaEdge 23XRV Start-Up, Operation And Maintenance Instructions Manual

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Fig. 38 — Typical Wet-Bulb Type
Vacuum Indicator
Check Chiller Tightness —
proper sequence and procedures for leak testing.
The 23XRV chillers are shipped with a full refrigerant and
oil charge. Units may be ordered with the refrigerant shipped
separately, and a 15 psig (103 kPa) nitrogen-holding charge in
each vessel. To determine if there are any leaks, the chiller
should be charged with a refrigerant tracer. Use an electronic
leak detector to check all flanges and solder joints after the
chiller is pressurized. If any leaks are detected, follow the leak
test procedure.
If the chiller is spring isolated, keep all springs blocked in
both directions to prevent possible piping stress and damage
during the transfer of refrigerant from vessel to vessel during
the leak test process, or any time refrigerant is being trans-
ferred. Adjust the springs when the refrigerant is in operating
condition and the liquid circuits are full.
Refrigerant Tracer —
environmentally acceptable refrigerant tracer for leak testing
with an electronic detector or halide torch.
Ultrasonic leak detectors can also be used if the chiller is
under pressure.
WARNING
Do not use air or oxygen as a means of pressurizing
the chiller. Mixtures of HFC-134a and air can undergo
combustion.
Due to regulations regarding refrig-
Leak Test Chiller —
erant emissions and the difficulties associated with separating
contaminants from refrigerant, Carrier recommends the follow-
ing leak test procedures. See Fig. 39 for an outline of the leak
test procedures. Refer to Fig. 40-43 during pumpout proce-
dures. See the Pumpout and Refrigerant Transfer Procedures
section on page 86. Refer to Tables 10 and 11 for temperature/
pressure relationships for HFC-134a refrigerant.
1. If the pressure readings are normal for chiller
condition:
a. Evacuate the holding charge from the vessels, if
present.
b. Raise the chiller pressure, if necessary, by adding
refrigerant until pressure is at equivalent saturated
pressure for the surrounding temperature.
Figure 39 outlines the
Carrier recommends the use of an
Never charge liquid refrigerant into the chiller if the pres-
sure in the chiller is less than 35 psig (241 kPa). Charge as
a gas only, with the cooler and condenser pumps running,
until this pressure is reached, using PUMPDOWN and
TERMINATE PUMPDOWN MODE on the ICVC. Flash-
ing of liquid refrigerant at low pressures can cause tube
freeze-up and considerable damage.
c. Leak test chiller as outlined in Steps 3-7.
2. If the pressure readings are abnormal for chiller
condition:
a. Prepare to leak test chillers shipped with refriger-
ant. If chiller is shipped with refrigerant, proceed
to Step 3.
b. Check for large leaks by connecting a nitrogen
bottle and raising the pressure to 30 psig (207
kPa). Soap test all joints. If the test pressure holds
for 30 minutes, prepare the test for small leaks
(Steps 2g to 2h).
c. Plainly mark any leaks which are found.
d. Release the pressure in the system.
e. Repair all leaks.
f. Retest only those joints that were repaired.
g. After successfully completing the test for large
leaks, remove as much nitrogen, air, and moisture
as possible, given the fact that small leaks may be
present in the system. This can be accomplished
by following the dehydration procedure, outlined
in the Chiller Dehydration section, page 71.
h. Slowly raise the system pressure to normal operat-
ing pressures for the refrigerant used in the chiller.
Proceed with the test for small leaks (Steps 3 to 7).
3. Check the chiller carefully with an electronic leak
detector or halide torch.
4. Leak Determination — If an electronic leak detector
indicates a leak, use a soap bubble solution, if possible,
to confirm. Total all leak rates for the entire chiller.
Leakage at rates greater than 1 lb/year (0.45 kg/year)
for the entire chiller must be repaired. Note total
chiller leak rate on the start-up report.
5. If no leak is found during initial start-up procedures,
complete the transfer of refrigerant gas from the
storage tank to the chiller. Retest for leaks.
6. If no leak is found after a retest
a. Transfer the refrigerant to the storage tank and
perform a standing vacuum test as outlined in the
Chiller Dehydration section, page 71.
b. If the chiller fails this test, check for large leaks
(Step 2b).
c. Dehydrate the chiller if it passes the standing
vacuum test. Follow the procedure in the
Chiller Dehydration section, page 71. Charge
chiller with refrigerant.
7. If a leak is found, pump the refrigerant back into the
storage tank, or if isolation valves are present, pump
into the vessel that is not leaking.
Transfer the refrigerant until chiller pressure is at least
equal to the pressure specified by the EPA under
40 CFR Part 82.
Repair the leak and repeat the procedure, beginning
from Step 2h to ensure a leaktight repair. If chiller is
opened to the atmosphere for an extended period,
evacuate it before repeating leak test.
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WARNING