30HXC UNITS — The 30HXC units are shipped from the
factory with a full charge of R-134a. Unit should not need
to be charged at installation unless a leak was detected in
Step 6 — Leak Test Unit section on page 26. If dehydration
and recharging is necessary, use industry standard practices
or refer to Carrier Standard Services Techniques Manual as
required.
30HXA UNITS — The 30HXA units are shipped with a hold-
ing charge of R-134a. The complete charge for the 30HXA,
the remote condenser(s), and interconnecting piping must be
field supplied.
To charge the 30HXA systems:
1. Add liquid charge into the cooler using the
1
⁄
4
-in. Schrader-
type fitting located on the tube going into the bottom
of the cooler. This fitting is located between the elec-
tronic expansion valve (EXV) (076-146 units) or the
economizer (161-186 units) and the cooler. Add approxi-
mately 2 lb/nominal ton (0.9 kg/nominal kW). This amount
of charge should be sufficient to allow the unit to start.
The approximate system charges are shown in Table 6.
2. Raise the compressor discharge to approximately 125 F
(51.7 C) saturated discharge temperature (185 psig
[1276 kPa]) by throttling the condenser air (or water) in-
take. Add charge until there is approximately 18 to 20 F
(10.0 to 11.1 C) of system subcooling (saturated dis-
charge temperature − actual temperature entering the EXV).
NOTE: On the units equipped with economizers
(30HXA161-186), the EXV is located inside the econo-
mizer so the temperature must be measured entering the
economizer (tube entering bottom of economizer).
3. Check for a clear sight glass. If the unit is not fully loaded,
the sight glass might be flashing. This is normal for a
partially-loaded unit.
Table 6 — 30HXA System Charge for
Start-Up
UNIT
30HXA
CIRCUIT A
CHARGE
CIRCUIT B
CHARGE
Lb
Kg
Lb
Kg
076
75
34.0
75
34.0
086
94
42.6
80
36.3
096
114
51.7
80
36.3
106
134
60.8
80
36.3
116
137
62.1
95
43.1
126
137
62.1
116
52.6
136
147
66.7
125
56.7
146
161
73.0
132
59.9
161
190
86.2
132
59.9
171
154
69.9
186
84.4
186
186
84.4
186
84.4
27
