Maintenance; Properties; Refrigerant - Carrier 19XRV Start-Up, Operation And Maintenance Instructions Manual

DISTILLING THE REFRIGERANT
1. Transfer the refligerant flom the chiller to the pumpout
storage tank as described in the Transfer the Refligerant
from Chiller to Pumpout Storage Tank section.
2. Equalize the refl'igerant pressure.
a. Turn on chiller water pumps and monitor chiller
pressures.
b. Close pumpout and storage tank valves 2, 4, 5, and
10, and close chiller charging valve 7; open chiller
isolation valve 11 and any other chiller isolation
valves, if present.
c. Open pumpout and storage tank valves 3 and 6;
open chiller valves la and lb.
VALVE la lb 2 3 4 5 6 7 10 11
CONDITION C C C C C
d. Gradually crack open valve 5 to increase chiller
pressure to 35 psig (241 kPa). Slowly feed refriger-
ant to prevent freeze-up.
e. Open valve 5 fully after the chiller pressure rises
above the freezing point of the refrigerant. Let the
storage tank and chiller pressure equalize.
3. Transfer remaining refrigerant.
a. Close valve 3.
b. Open valve 2.
c. Turn on pumpout condenser water.
d. Run the pumpout compressor until the storage tank
pressure reaches 5 psig (34 kPa), 18 in. Hg vacuum
(41 kPa absolute) in Manual or Automatic mode.
e. Turn off the pumpout compressor.
f. Close valves la, lb, 2, 5, and 6.
g. Turn off pumpout condenser water.
VALVE la lb 2 3 4 5 6 7 10 11
CONDITION C C C C C C C C C
4. Drain the contaminants from the bottom of the storage
tank into a containel: Dispose of contaminants safely.
GENERAL MAINTENANCE
Refrigerant Properties -- The standard refrigerant for
the 19XRV chiller is HFC-134a. At normal atmospheric
pressure, HFC-134a refrigerant will boil at -14 F (-25 C) and
must, therefore, be kept in pressurized containel.s or storage
tanks. The refrigerant is practically odorless when mixed with
air and is noncombustible at atmospheric pressure. Read the
Material Safety Data Sheet and the latest ASHRAE Safety
Guide for Mechanical Refrigeration to learn more about safe
handling of this refrigerant.
Refrigerant HFC-134a will dissolve oil and some nonme-
tallic materials, dq the skin, and, in heavy concentrations,
may displace enough oxygen to cause asphyxiation. When
handling this refrigerant, protect the hands and eyes and
avoid breathing fumes.
Adding Refrigerant--Follow
the procedures de-
scribed in Trim Refrigerant Charge section, page 75.
Always use the compressor pumpdown function in the
Control Test table to turn on the cooler pump and lock out
the compressor when transfen'ing refrigerant. Liquid reflig-
emnt may flash into a gas and cause water in the heater
exchanger tubes to freeze when the chiller pressure is
below 35 psig (241 kPa) for HFC-134a, resulting in equip-
ment damage.
Removing Refrigerant
-- If the optional pumpout sys-
tem is used, the 19XRV refrigerant charge may be transferred
to a pumpout storage tank or to the chiller condenser or cooler
vessels. Follow the procedures in the Pumpout and Refrigerant
Transfer Procedmes section when transferringrefrigerant from
one vessel to another:
Adjusting the Refrigerant Charge -- If the addi-
tion
or removal of refrigerant is required to improve chiller
performance, follow the procedures given under the Trim
Refrigerant Chmge section, page 75.
Refrigerant Leak Testing
-- Because HFC-134a
re-
frigerant
is above atmospheric pressure at room temperature,
leak testing can be performed with refrigerant in the chillel:
Use an electronic halide leak detector, soap bubble solution, or
ultrasonic leak detectol: Ensure that the room is well ventilated
and free from concentration of refrigerant to keep false read-
ings to a minimum. Before making aW necessguy repairs to a
leak, transfer all refrigerant from the leaking vessel.
Leak Rate
-- It is recommended by ASHRAE that chillers
be taken off line immediately and repaired if the refrigerant
leak rate for the entire chiller is more than 10% of the operating
refrigerant charge per yegu:
In addition, Carrier recommends that leaks totalling less
than the above rate but more than a rate of 0.1% of the total
chguge per yegu should be lepaired during annu_d maintenance
or whenever the refrigerant is transferred for other service
work.
Test After Service, Repair, or Major Leak- If
all the refrigerant has been lost or if the chiller has been opened
for service, the chiller or the affected vessels must be pressure
tested and leak tested. Refer to the Leak Test Chiller section to
perform a leak test.
HFC-134a refrigerant should not be mixed with air or
oxygen and pressurized for leak testing. In general, this
refrigerant should not be present with high concentrations
of air or oxygen above atmospheric pressures, because the
mixture can undergo combustion, which could result in
serious personal injury or death.
TESTING WITH REFRIGERANT TRACER -- Use an en-
vironmentally acceptable refrigerant as a tracer for leak test
procedures. Use dry nitrogen to raise the machine pressure to
leak testing levels.
TESTING WITHOUT REFRIGERANT TRACER -- Anoth-
er method of leak testing is to pressurize with nitrogen only and
to use a soap bubble solution or an ultrasonic leak detector to
determine if leaks are present.
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