50
Leak Test Chiller —
Due to regulations regarding refrig-
erant emissions and the difficulties associated with separating
contaminants from refrigerant, Carrier recommends the follow-
ing leak test procedures. See Fig. 31 for an outline of the leak
test procedures. Refer to Fig. 24 and 25 during pumpout proce-
dures. See the Pumpout and Refrigerant Transfer Procedures
Section on page 69. Refer to Tables 6A-6D for temperature/
pressure relationships for HCFC-22 and HFC-134a refriger-
ants. See Fig. 32-35.
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.
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 2h.
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 - h).
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 58.
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 - 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 stor-
age 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 58.
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. 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
40CFR 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.
Never charge liquid refrigerant into the chiller if the pres-
sure in the chiller is less than 68 psig (469 kPa) [35 psig
(241 kPa)]. Charge as a gas only, with the cooler and con-
denser pumps running, until this pressure is reached, using
PUMPDOWN and TERMINATE PUMPDOWN/LOCK-
OUT mode on the PIC. Flashing of liquid refrigerant at
low pressures can cause tube freeze-up and considerable
damage.
Fig. 30 — Typical Wet-Bulb Type
Vacuum Indicator
Содержание 23XL
Страница 18: ...18 Fig 15 Control Panel Fig 16 Power Panel ...
Страница 51: ...51 Fig 31 23XL Leak Test Procedure ...
Страница 52: ...52 Fig 32 Typical Optional Pumpout System Piping Schematic with Storage Tank TC Frame 1 and 2 Chillers ...
Страница 53: ...53 Fig 33 Typical Optional Pumpout System Piping Schematic With Storage Tank TD Frame 4 Chillers ...
Страница 54: ...54 Fig 34 Typical Optional Pumpout System Piping Schematic Without Storage Tank TC Frame 1 and 2 Chillers ...
Страница 55: ...55 Fig 35 Typical Optional Pumpout System Piping Schematic Without Storage Tank TD Frame 4 Chillers ...
Страница 99: ...99 Fig 49 Benshaw Inc Solid State Unit Mounted Starter Wiring Schematic Low Voltage ...