41
Operating the Optional Pumpout Unit (Fig. 37)
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 50. The pumpout unit control wir-
ing schematic is detailed in Fig. 38.
TO READ REFRIGERANT PRESSURES (during pumpout or
leak testing):
1. The display on the chiller control panel is suitable for
determining refrigerant-side pressures and low (soft) vac-
uum. To assure the desired range and accuracy when mea-
suring evacuation and dehydration, use a quality vacuum
indicator or manometer. This can be placed on the
Schrader connections on each vessel by removing the
pressure transducer (Fig. 3-5).
2. To determine pumpout storage tank pressure, a 30 in. Hg
vacuum -0-400 psi (101-0-2758 kPa) gage is attached to
the storage tank.
3. Refer to Fig. 33 and 34 for valve locations and numbers.
POSITIVE PRESSURE CHILLERS WITH STORAGE TANKS
In the Valve/Condition tables that accompany these instruc-
tions, the letter “C” indicates a closed valve. Figures 33 and 34
show the locations of the valves.
Fig. 37 — Pumpout Unit
Fig. 38 — Pumpout Unit Wiring Schematic
DANGER
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 the release of refrigerant which will result in
personal injury or death.
CAUTION
Do not mix refrigerants from chillers that use different
compressor oils. Compressor damage can result.
CAUTION
Transfer, addition, or removal of refrigerant in spring-isolated
chillers may place severe stress on and damage external piping
if springs have not been blocked in both up and down directions.
CAUTION
Always run chiller cooler and condenser water pumps and
always charge or transfer refrigerant as a gas when chiller
vessel pressure is less than 35 psig (241 kPa). Below these
pressures, liquid refrigerant flashes into gas, resulting in ex-
tremely low temperatures in the cooler/condenser tubes and
possibly causing tube freeze-up.
a23-1546
COMPRESSOR
OIL
SEPARATOR
CONDENSER
LEAVING
WATER
ENTERING
WATER
VALVE
5
VALVE
4
VALVE
2
CONTROL
PANEL
FRAME
ASSEMBLY
OIL
HEATER
VALVE
3
OIL FILL
FITTING
2 OL
2 OL
2 OL
MTR-1
L1
L2
PUMP OUT
COMPRESSOR
CRANKCASE HEATER
240-600v
27-40 WATT
GND
H1 H4
X1 X2
X2
HIGH PRESSURE
SAFETY
NC OPEN > 185psig
CONTROL POWER
TRANSFORMER
XFMR-1
69 VA
C
C
C
8
7
HTR-1
FU1
0.25A
FU2
0.25A
FU3
0.5A
12
2
2
3
4
SS-1
OFF
AUTO ON
LOW PRESSURE CONTROL
NC OPEN < 7 psia (-15.7 in. HG)
CLOSE > 9 psia (-11.6 in. HG)
5
C
X2
6
FIELD
POWER
SUPPLY
L1
L2
L3
LEGEND
C — Contactor
FU — Fuse
GND — Ground
HTR — Heater
MTR — Motor
NC — Normally Closed
OL — Overload
SS — Selector Switch
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