Refrigerant Tracer; Leak Test Chiller; Standing Vacuum Test - Carrier AquaEdge 19XR Series Start-Up, Operation And Maintenance Instructions Manual

Refrigerant Tracer

Carrier recommends the use of an environmentally acceptable
refrigerant tracer for leak testing with an electronic detector.
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, re-
sulting in equipment damage and possible personal injury.

Leak Test Chiller

Due to regulations regarding refrigerant emissions and the diffi-
culties associated with separating contaminants from the refriger-
ant, Carrier recommends the following leak test procedure. Refer
to Tables 6 and 7 for refrigerant pressure/temperature values.
1. If the pressure readings are normal for the 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 the equivalent saturated
pressure for the surrounding temperature. Follow
pumpout procedures in the Transfer Refrigerant from
Pumpout Storage Tank to Chiller section, Steps 1a-e,
page 44.
CAUTION
Never charge liquid refrigerant into the chiller if the pressure
in the chiller is less than 35 psig (241 kPa) for HFC-134a or
less than 39 psig (268 kPa) for R-513A. Charge as a gas only,
with the cooler and condenser pumps running, until this pres-
sure is reached, using PUMPDOWN/LOCKOUT (located in
the Maintenance menu) and TERMINATE LOCKOUT mode
on PIC 6 control interface. Flashing of liquid refrigerant at low
pressures can cause tube freeze-up and considerable damage.
c. Leak test chiller as outlined in Steps 3 to 9.
2. If the pressure readings are abnormal for the chiller condition:
a. Prepare to leak test chillers shipped with refrigerant
(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 and 2h).
c. Plainly mark any leaks that are found.
d. Release the pressure in the system.
e. Repair all leaks.
f. Retest the joints that were repaired.
g. After successfully completing the test for large leaks,
remove as much nitrogen, air, and moisture as possi-
ble, 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 28.
h. Slowly raise the system pressure to a maximum of
160 psig (1103 kPa) but no less than 35 psig
(241 kPa) for HFC-134a by adding refrigerant (below
35 psig refrigerant must be added as a gas). Proceed
with the test for small leaks (Steps 3 to 9).
3. Check the chiller carefully with an electronic leak detector
or soap bubble solution.
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 0.1% of the total charge per year must be
repaired. Note the total chiller leak rate on the start-up report.
5. If no leak is found during the 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 per-
form a standing vacuum test as outlined in the Stand-
ing Vacuum Test section, below.
b. If the chiller fails the standing vacuum test, check for
large leaks (Step 2b).
c. If the chiller passes the standing vacuum test, dehy-
drate the chiller. Follow the procedure in the Chiller
Dehydration section, page 28. Charge the chiller with
refrigerant.
7. If a leak is found after a retest, pump the refrigerant back
into the storage tank or, if isolation valves are present,
pump the refrigerant into the non-leaking vessel. See the
Transfer Refrigerant from Pumpout Storage Tank to
Chiller section on page 44.
8. Transfer the refrigerant until the chiller pressure is at
18 in. Hg (40 kPa absolute).
9. Repair the leak and repeat the procedure, beginning from
Step 2h, to ensure a leak-tight repair. (If the chiller is
opened to the atmosphere for an extended period, evacuate
it before repeating the leak test.)

Standing Vacuum Test

When performing the standing vacuum test or chiller dehydration,
use a manometer or a digital vacuum gage. Dial gages cannot indi-
cate the small amount of acceptable leakage during a short period
of time.
1. Attach an absolute pressure manometer or digital vacuum
gage to the chiller.
2. Evacuate the vessel to at least 18 in. Hg vac (41 kPa
[abs]), using a vacuum pump or the pumpout unit.
3. Valve off the pump to hold the vacuum and record the
manometer or indicator reading.
4. Check the leakage rate.
a. If the leakage rate is less than 0.05 in. Hg (0.17 kPa)
in 24 hours, the chiller is sufficiently tight.
b. If the leakage rate exceeds 0.05 in. Hg (0.17 kPa) in
24 hours, re-pressurize the vessel and test for leaks if
refrigerant is available. If not, use nitrogen and a
refrigerant tracer. Raise the vessel pressure in incre-
ments until the leak is detected. If refrigerant is used,
the maximum gas pressure is approximately 70 psig
(483 kPa) for HFC-134a at normal ambient tempera-
ture. If nitrogen is used, limit the leak test pressure to
160 psig (1103 kPa) maximum.
5. Repair the leak, retest, and proceed with dehydration.
26