69
PUMPOUT AND REFRIGERANT
TRANSFER PROCEDURES
Preparation —
The 23XL may come equipped with an
optional pumpout storage tank, pumpout system, or pumpout
compressor. The refrigerant can be pumped for service work to
either the chiller compressor evaporator vessel or chiller con-
denser vessel by using the optional pumpout system. If a
pumpout storage tank is supplied, the refrigerant can be isolat-
ed in the storage tank. The following procedures describe how
to transfer refrigerant from vessel to vessel and perform chiller
evacuations.
Operating the Optional Pumpout Unit
1. Be sure that the suction and the discharge service
valves on the optional pumpout compressor are open
(backseated) during operation. Rotate the valve stem
fully counterclockwise to open. Frontseating the valve
closes the refrigerant line and opens the gage port to
compressor pressure.
2. Ensure 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 unit compressor
sight glass under all operating conditions and during
shutdown. If oil is low, add oil as described under
Optional Pumpout System Maintenance section,
page 76. The pump-out unit control wiring schematic
is detailed in Fig. 38.
TO READ REFRIGERANT PRESSURES during pumpout or
leak testing:
1. The CVC display on the chiller control panel is suit-
able for determining refrigerant-side pressures and low
(soft) vacuum. To assure the desired range and accu-
racy when measuring evacuation and dehydration, use
a quality vacuum indicator or manometer. This can be
placed on the Schrader connections on each vessel
(Fig. 11 and 12) by removing the pressure transducer.
2. To determine pumpout storage tank pressure, a 30 in.
–0-400 psi (–101-0-2769 kPa) gage is attached to the
storage tank.
3. Refer to Fig. 32-35, and 39 for valve locations and-
numbers.
Always run the chiller cooler and condenser water pumps
and always charge or transfer refrigerant as a gas when the
chiller pressure is less than 30 psig (207 kPa). Below these
pressures, liquid refrigerant flashes into gas, resulting in
extremely low temperatures in the cooler/condenser tubes
and possibly causing tube freeze-up.
During transfer of refrigerant into and out of the optional
storage tank, carefully monitor the storage tank level gage.
Do not fill the tank more than 90% of capacity to allow for
refrigerant expansion. Overfilling may result in damage to
the tank or personal injury.
Do not mix refrigerants from chillers that use different
compressor oils. Compressor damage can result.
Transfer, addition, or removal of refrigerant in spring-
isolated chillers may place severe stress on external piping
if springs have not been blocked in both up and down
directions.
OIL RETURN
LINE
CONNECTION
CONDENSER
WATER
CONNECTIONS
REFRIGERANT
INLET VALVE
LEGEND
*Bimetal thermal protector imbedded in motor winding.
Fig. 38 — 23XL Pumpout Unit Wiring Schematic
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
Fig. 39 — Optional Pumpout Unit