81
Table 16 — Refrigerant Charges, Frame Sizes 3-5
Table 17 — Refrigerant Charges, Frame Sizes A,B
CHILLER SHIPPED WITH HOLDING CHARGE — Use the
CONTROL TEST TERMINATE LOCKOUT function to
monitor conditions and start the pumps.
If the chiller has been shipped with a holding charge, the
refrigerant is added through the refrigerant charging valve
(Fig. 40-43, valves 1a and 1b) or to the pumpout charging con-
nection. First evacuate the nitrogen holding charge from the
chiller vessels. Charge the refrigerant as a gas until the system
pressure exceeds 35 psig (141 kPa) for HFC-134a. After the
chiller is beyond this pressure the refrigerant should be charged
as a liquid until all the recommended refrigerant charge has
been added.
TRIMMING REFRIGERANT CHARGE — Th e 23 XR V
chiller is shipped with the correct charge for the design duty of
the chiller. The LTD (leaving temperature difference) between
the EVAP REFRIG LIQUID TEMP and LEAVING CHILLED
LIQUID can be checked against the design conditions to con-
firm that the charge is correct. In the case where leaks have
been found and corrected and the LTD is greater than about
4° F (2.2° C) above design, add refrigerant until the full load
design LTD is approached. (A high cooler LTD can also be
caused by dirty tubes, water box division plate bypass, a par-
tially closed liquid isolation valve, or the float valve.)
Trimming the charge can best be accomplished when the
design load is available. The calibration of the EVAP REFRIG
LIQUID TEMP and LEAVING CHILLED LIQUID tempera-
ture sensors should be confirmed prior to checking for proper
cooler LTD. Compare the difference between EVAP REFRIG
LIQUID TEMP and LEAVING CHILLED LIQUID tempera-
tures to the chiller design conditions. Add or remove refriger-
ant, if necessary, to bring the cooler leaving temperature
difference to design conditions or within minimum differential.
Check for low load oil recovery after making adjustments to
the refrigerant charge. The bubbling mixture of refrigerant and
oil mixture should be visible through the vaporizer sight glass
at low load when the oil reclaim valve is open. If a bubbling
mixture is not observed when the oil reclaim valve is open, add
refrigerant.
The preferred location at which refrigerant should be added
directly into the chiller is through the service valves on top of
the cooler condenser. if these valves are not accessible due to
presence of an attached pumpdown unit which does not have a
storage tank, slowly add charge through the valve connected to
the side of the condenser drain float sump. Adding charge
through the cooler refrigerant pumpout valve at the base of the
cooler (off the liquid line) may force debris into the condenser
float valve and is not recommended.
FRAME SIZE
COOLER
LENGTH
FT (M)
COOLER
CODE
CHARGE AMOUNT (R-134a)
WITH ECONOMIZER WITHOUT ECONOMIZER
lb (± 25 lb) kg (± 11 kg) lb (± 25 lb) kg (± 11 kg)
3
12
(3.6)
30 800 363 650 295
31 800 363 650 295
32 800 363 650 295
14
(4.3)
35 910 413 760 345
36 910 413 760 345
37 910 413 760 345
4
12
(3.6)
40 900 408 750 340
41 900 408 750 340
42 900 408 750 340
14
(4.3)
45 1015 460 865 392
46 1015 460 865 392
47 1015 460 865 392
5
12
(3.6)
50 1250 567 1100 499
51 1250 567 1100 499
52 1250 567 1100 499
14
(4.3)
55 1430 649 1280 581
56 1430 649 1280 581
57 1430 649 1280 581
FRAME SIZE
COOLER LENGTH
FT (M)
CHARGE AMOUNT (R-134a)
WITH ECONOMIZER WITHOUT ECONOMIZER
lb (± 25 lb) kg (± 11 kg) lb (± 25 lb) kg (± 11 kg)
A1
12
(3.6)
840 381 820 372
A2
860 390 840 381
A3
880 399 860 390
A4
900 408 880 399
A5
930 422 910 413
A6
960 435 940 426
B1
14
(4.3)
950 431 930 422
B2
970 440 950 431
B3
1000 454 980 445
B4
1020 463 1000 454
B5
1060 481 1040 472
B6
1090 494 1070 485
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