71
Chillers with Storage Tanks —
If the chiller has a
separate storage tank, or the chiller does not have isolation
valves, refer to the following procedure. See Fig. 32-35.
TRANSFER REFRIGERANT FROM PUMPOUT STOR-
AGE TANK TO CHILLER
1. Equalize refrigerant pressure.
a.
Use the PIC II terminate lockout function on the
PUMPDOWN LOCKOUT screen, accessed from
the CONTROL TEST table to turn on the water
pumps and monitor pressures.
b.
Close pumpout unit valves 2, 4, 5, 8, and 10, and
close chiller charging valve 7; open chiller isola-
tion valves 11, 12, 13, and 14 (if present).
c.
Open pumpout unit/storage tank valves 3 and 6,
open chiller valves 1a and 1b.
d.
Slowly open valve 5 to increase chiller pressure to
68 psig 35 psig (141 kPa) for HFC-134a. Feed
refrigerant slowly 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.
2. Transfer the remaining refrigerant.
a.
Close valve 5 and open valve 4.
b.
Turn off the chiller water pumps using the CVC
(or manually, if necessary).
c.
Turn off the pumpout condenser water, and turn
on the pumpout compressor to push liquid out of
the storage tank.
d.
Close liquid line valve 7.
e.
Turn off the pumpout compressor.
f.
Close valves 3 and 4.
g.
Open valves 2 and 5.
h.
Turn on the pumpout condenser water.
i.
Run the pumpout compressor until the pumpout
storage tank pressure reaches 5 psig (34 kPa)
(18 in. Hg [40 kPa absolute] if repairing the tank).
j.
Turn off the pumpout compressor.
k.
Close valves 1a, 1b, 2, 5, 6, and 10.
l.
Turn off pumpout condenser water.
TRANSFER REFRIGERANT FROM CHILLER TO
PUMPOUT STORAGE TANK
1. Equalize refrigerant pressure.
a.
Valve positions:
b.
Slowly open valve 5. When the pressures are
equalized, open liquid line valve 7 to allow liquid
refrigerant to drain by gravity into the pumpout
storage tank.
2. Transfer the remaining liquid.
a.
Turn off the pumpout condenser water. Place the
valves in the following positions:
b.
Run the pumpout compressor for approximately
30 minutes; then close valve 10.
c.
Turn off the pumpout compressor.
3. Remove any remaining refrigerant.
a.
Turn on the chiller water pumps using the PUMP-
DOWN LOCKOUT screen, accessed from the
CONTROL TEST table. Turn on the pumps man-
ually, if they are not controlled by the PIC II.
b.
Turn on the pumpout condenser water.
c.
Place valves in the following positions:
d.
Run the pumpout compressor until the chiller
pressure reaches 30 psig (207 kPa) for HFC-134a.
Then, shut off the pumpout compressor. Warm
condenser water will boil off any entrapped liquid
refrigerant and the chiller pressure will rise.
e.
When the pressure rises to 40 psig (276 kPa) for
HFC-134a, turn on the pumpout compressor until
the pressure again reaches 30 psig (207 kPa), and
then turn off the pumpout compressor. Repeat this
process until the pressure no longer rises. Then,
turn on the pumpout compressor and pump until
the pressure reaches18 in. Hg. (40 kPa absolute).
f.
Close valves 1a, 1b, 3, 4, 6, 7, and 10.
g.
Turn off the pumpout condenser water and con-
tinue to use the PIC II PUMPDOWN LOCKOUT
screen functions, which lock out the chiller com-
pressor for operation.
4. Establish a vacuum for service.
To conserve refrigerant, operate the pumpout compres-
sor until the chiller pressure is reduced to 18 in. Hg
vac., ref 30 in. bar. (40 kPa abs.) following Step 3e.
If the chilled water and condenser water pumps are not
controlled by the PIC II, these pumps must be started and
stopped manually at the appropriate times during the refrig-
erant transfer procedure.
VALVE
1a 1b 2 3 4 5 6 7 8 10 11 12 13 14
CONDITION
C
C C
C C C
Follow steps D and E carefully to prevent damage from
freeze-up.
VALVE
1a 1b 2 3 4 5 6 7 8 10 11 12 13 14
CONDITION
C
C
C
VALVE
1a 1b 2 3 4 5 6 7 8 10 11 12 13 14
CONDITION
C
C
VALVE
1a 1b 2 3 4 5 6 7 8 10 11 12 13 14
CONDITION
C C
C C
VALVE
1a 1b 2
3
4
5
6
7
8 10 11 12 13 14
CONDITION C C C C C C C C C C
VALVE
1a 1b 2 3 4 5 6 7 8 10 11 12 13 14
CONDITION
C
C C
C C
VALVE
1a 1b 2 3 4 5 6 7 8 10 11 12 13 14
CONDITION
C
C
C
VALVE
1a 1b 2 3 4 5 6 7 8 10 11 12 13 14
CONDITION
C C
C
VALVE
1a 1b 2 3 4 5 6 7 8 10 11 12 13 14
CONDITION
C C
C C
VALVE
1a 1b 2 3 4 5 6 7 8 10 11 12 13 14
CONDITION
C
C
C C
VALVE
1a 1b 2 3 4 5 6 7 8 10 11 12 13 14
CONDITION C C C C C C C C C C