General Maintenance; Refrigerant Properties; Adding Refrigerant; Adjusting The Refrigerant Charge - Carrier AquaEdge 19DV series Start-Up, Operation And Maintenance Instructions Manual

GENERAL MAINTENANCE

Refrigerant Properties —
the 19DV chiller is HFO R-1233zd(E). At normal atmospheric
pressure, HFO R-1233zd(E) will boil at 65°F (18°C) and must,
therefore, be kept in pressurized containers 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.
DANGER
HFO R-1233zd(E) 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 —
scribed in Trim Refrigerant Charge section, page 43.
CAUTION
Always use the compressor pumpdown function in the
PUMPDOWN/LOCKOUT feature to turn on the cooler
pump and lock out the compressor when transferring
refrigerant. Liquid refrigerant may flash into a gas and
cause possible freeze-up when the chiller pressure is below
–15 in. Hg (–53 kPa) for HFO R-1233zd(E).
Adjusting the Refrigerant Charge —
tion or removal of refrigerant is required to improve chiller per-
formance, follow the procedures given under the Trim Refrig-
erant Charge section, page 43.
Refrigerant Leak Testing —
erant system operates in vacuum non-condensables will enter
the cooling systems. The PIC5 HMI will issue an alert indicat-
ing excessive purge operation. Leaks, which cause frequent
purge cycles, should be repaired without delay. Non-condens-
able gas in the machine causes higher than normal condenser
pressure, compressor surge at start-up and frequent purge cy-
cles, so locate and repair any leaks as soon as possible. Before
making any necessary repairs to a leak, transfer all refrigerant
from the vessel.
It is recommended by ASHRAE that chillers
Leak Rate —
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 year.
Carrier recommends that leaks totaling less than the above
rate but more than a rate of 0.1% of the total charge per year
should be repaired during annual maintenance or whenever the
refrigerant is transferred for other service work.
Test After Service, Repair, or Major Leak —
the refrigerant has been lost or if the chiller has been opened for
service, the chiller or the affected vessels must be pressure test-
ed and leak tested. Refer to the Leak Test Chiller section on
page 18 to perform a leak test.
The standard refrigerant for
Follow the procedures de-
If the addi-
Since parts of the refrig-
If all
HFO R-1233zd(E) 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.
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 — An-
other 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.
TO PRESSURIZE WITH DRY NITROGEN
NOTE: Pressurizing with dry nitrogen for leak testing should
not be done if the full refrigerant charge is in the vessel
because purging the nitrogen is very difficult.
1. Connect a copper tube from the pressure regulator on the
cylinder to the refrigerant charging valve. Never apply
full cylinder pressure to the pressurizing line. Follow the
listed sequence.
2. Open the charging valve fully.
3. Slowly open the cylinder regulating valve.
4. Observe the pressure gage on the chiller and close the
regulating valve when the pressure reaches test level.
Do not exceed maximum allowable test pressure 45 psig
(310 kPa) for units marked 57 MAWP to allow for plen-
ty of margin to avoid from bursting the rupture discs.
5. Close the charging valve on the chiller. Remove the cop-
per tube if it is no longer required.
Repair the Leak, Retest, and Apply Standing
Vacuum Test —
leaks with an electronic halide leak detector, soap bubble solu-
tion, or an ultrasonic leak detector. Bring the chiller back to at-
mospheric pressure, repair any leaks found, and retest.
After retesting and finding no leaks, apply a standing vacu-
um test. Then dehydrate the chiller. Refer to the Standing Vacu-
um Test and Chiller Dehydration sections (pages 18 and 20) in
the Before Initial Start-Up section.
Checking Guide Vanes —
down, when the chiller is off, the guide vanes are closed.
Complete the following steps to adjust position if required
(see Fig. 39-40):
1. Remove the set screw in the guide vane coupling.
2. Loosen the holddown bolts on the guide vane actuator.
3. Pull the guide vane actuator away from the suction
housing.
41
WARNING
After pressurizing the chiller, test for
During normal shut-