Carrier AquaEdge 23XRV Start-Up, Operation And Maintenance Instructions Manual page 40

COOLER
FRAME SIZE LENGTH
FT (M)
12
(3.6)
3
14
(4.3)
12
(3.6)
4
14
(4.3)
12
(3.6)
5
14
(4.3)
FRAME SIZE
A1
A2
A3
A4
A5
A6
B1
B2
B3
B4
B5
B6
CHILLER SHIPPED WITH HOLDING CHARGE
If the chiller has been shipped with a holding charge, the refriger-
ant is added through the refrigerant charging valve (Fig. 27-30,
valves 1a and 1b) or to the pumpout charging connection. 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 R-134a or 39 psig (268 kPa) for R-513A.
After the chiller is beyond this pressure the refrigerant should be
charged as a liquid until all the recommended refrigerant charge
has been added. Ensure that pumps are running while system is
being charged.
TRIMMING REFRIGERANT CHARGE
The 23XRV chiller is shipped with the correct charge for the de-
sign duty of the chiller. The Evaporator Approach (difference be-
tween Saturated Refrigerant Temp and Leaving Water Temp) can
be checked against the design conditions to confirm that the
charge is correct. In the case where leaks have been found and cor-
rected and the Evaporator Approach is greater than about 4°F
(2.2°C) above design, add refrigerant until the full load design
LTD is approached. (A high Evaporator Approach can also be
caused by dirty tubes, water box division plate bypass, a partially
closed liquid isolation valve, or the float valve.)
Table 10 — Refrigerant Charges, Frame Sizes 3-5
COOLER CODE
lb (± 25 lb)
30
31
32
35
36
37
40
41
42
45
46
47
50
51
52
55
56
57
Table 11 — Refrigerant Charges, Frame Sizes A,B
COOLER LENGTH
FT (M)
lb (± 25 lb)
12
(3.6)
14
(4.3)
CHARGE AMOUNT (R-134a, R-513A)
WITH ECONOMIZER
kg (± 11 kg)
800 363
800 363
800 363
910 413
910 413
910 413
900 408
900 408
900 408
1015 460
1015 460
1015 460
1250 567
1250 567
1250 567
1430 649
1430 649
1430 649
CHARGE AMOUNT (R-134a, R-513A)
WITH ECONOMIZER
kg (± 11 kg)
840 381
860 390
880 399
900 408
930 422
960 435
950 431
970 440
1000 454
1020 463
1060 481
1090 494
Trimming the charge can best be accomplished when the de-
sign load is available. The calibration of the Evaporator Refrig-
erant Pressure and Leaving Chilled Water Temp should be
confirmed prior to checking for proper Evaporator Approach.
Compare the difference between Evaporator Refrigerant Temp
and Leaving Chilled Water Temp to the chiller design condi-
tions. Add or remove refrigerant, 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 di-
rectly into the chiller is through the service valves on top of the
cooler or 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.
40
WITHOUT ECONOMIZER
lb (± 25 lb) kg (± 11 kg)
650 295
650 295
650 295
760 345
760 345
760 345
750 340
750 340
750 340
865 392
865 392
865 392
1100 499
1100 499
1100 499
1280 581
1280 581
1280 581
WITHOUT ECONOMIZER
lb (± 25 lb) kg (± 11 kg)
820 372
840 381
860 390
880 399
910 413
940 426
930 422
950 431
980 445
1000 454
1040 472
1070 485