Carrier 19XL - Manual (Page 59)

PUMPOUT AND REFRIGERANT TRANSFER
PROCEDURES
Preparation — The 19XL may come equipped with
an optional storage tank or pumpout system, or a pump-
out compressor. The refrigerant can be pumped for service
work to either the cooler/compressor vessel or the condenser
vessel by using the optional pumpout system. If a storage
tank is supplied, the refrigerant can be isolated in the
external storage tank. The following procedures describe how
to transfer refrigerant from vessel to vessel and perform chiller
evacuations.
Operating the Optional Pumpout Compressor
1. Be sure that the suction and the discharge service valves
on the optional pumpout compressor are open (back-
seated) during operation. Rotate the valve stem fully coun-
terclockwise to open. Frontseating the valve closes the
refrigerant line and opens the gage port to compressor
pressure.
2. Make sure that the compressor holddown bolts have been
loosened to allow free spring travel.
3. Open the refrigerant inlet valve on the pumpout
compressor.
4. Oil should be visible in the pumpout compressor sight
glass under all operating conditions and during shut-
down. If oil is low, add oil as described under Optional
Pumpout System Maintenance section, page 65. The
pumpout unit control wiring schematic is detailed in
Fig. 34.
TO READ REFRIGERANT PRESSURES during pumpout
or leak testing:
1. The LID display on the chiller control center is suitable
for determining refrigerant-side pressures and low (soft)
vacuum. For evacuation or dehydration measurement, use
a quality vacuum indicator or manometer to ensure the
desired range and accuracy. This can be placed on the
Schrader connections on each vessel by removing the pres-
sure transducer.
2. To determine storage tank pressure, a 30 in.-0-400 psi
(-101-0-2760 kPa) gage is attached to the vessel.
3. Refer to Fig. 27, 28, and 35 for valve locations and
numbers.
Transfer, addition, or removal of refrigerant in spring-
isolated chillers may place severe stress on external pip-
ing if springs have not been blocked in both up and down
directions.
Chillers with Pumpout Storage Tanks — If the
chiller has isolation valves, leave them open for the follow-
ing procedures. The letter ‘‘C’’ describes a closed valve. See
Fig. 16, 17, 27, and 28.
TRANSFER REFRIGERANT FROM STORAGE TANK TO
CHILLER
1. Equalize refrigerant pressure.
a. Use the Control Test Terminate Lockout to turn on
water pumps and monitor pressures.
b. Close pumpout unit/storage tank valves 2, 4, 5, 8, and
10 and close chiller charging valve 7; open chiller iso-
lation valves 11, 12, 13, and 14 (if present).
c. Open pumpout unit/storage tank valves 3 and 6, open
chiller valves 1a and 1b.
VALVE 1a 1b 2 3 4 5 6 7 8 10 11 12 13 14
CONDITION C C C C C C
d. Gradually crack open valve 5 to increase chiller pres-
sure to 68 psig (469 kPa), [35 psig (141 kPa)]. Slowly
feed refrigerant to prevent freeze up.
e. Open valve 5 fully after the pressure rises above the
freeze point of the refrigerant. Open liquid line valves
7 and 10 until refrigerant pressure equalizes.
VALVE 1a 1b 2 3 4 5 6 7 8 10 11 12 13 14
CONDITION C C C
LEGEND
C — Contactor
FU — Fuse, 3 Amps
HP — High-Pressure Cutout
OL — Compressor Overload
T’STAT — Internal Thermostat
Compressor Terminal
Contactor Terminal
Overload Terminal
Pumpout Unit Terminal
*Bimetal thermal protector imbedded in motor winding.
Fig. 34 — 19XL Pumpout Unit
Wiring Schematic
OIL RETURN
LINE
CONNECTION
CONDENSER
WATER
CONNECTIONS
REFRIGERANT
INLET VALVE
VENT VALVE 8
PUMPOUT
STARTER
PANEL
Fig. 35 — Optional Pumpout Unit
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