Sterlco 30RA Outdoor Air Cooled Central Chillers 10-60 Tons - Manual (Page 24)

24
Step 7 — Refrigerant Circuit
LEAK TESTING — Units are shipped with complete operat-
ing charge of R-22 (refer to Physical Data tables) and should be
under sufficient pressure to conduct a leak test. Perform a leak
test to ensure that leaks have not developed during unit
shipment. Dehydration of the system is not required unless the
entire refrigerant charge has been lost. Compressor oil equal-
ization line fittings use O-ring face seal fittings. If a leak is
detected at these fittings, tighten fitting
1 /
4
turn. If leak persists,
open system and inspect the O-ring surface for foreign material
or damage. Do not reuse O-rings. Repair any leak found using
good refrigeration practice.
DEHYDRATION — Refer to Sterlco Standard Service Tech-
niques Manual, Chapter 1, Refrigerants, Sections 6 and 7 for
details. Do not use compressor to evacuate system.
REFRIGERANT CHARGE (Refer to Tables 1A-1D) —
Immediately ahead of filter drier in each circuit is a factory-
installed liquid line service valve. Each valve has a
1 /
4
-in.
Schrader connection for charging liquid refrigerant.
.
If unit is equipped with a Motormaster® V control, the pres-
sure transducer has to be removed from the liquid line Schrader
connection to allow for gauge access.
The compressors are provided with a 1 /
4
-in. Schrader fitting
for connecting to low-side system pressure. The location of the
suction access port is shown in Fig. 20.
When charging, circulate water through the cooler at all
times to prevent freezing. Freezing damage is considered
abuse and may void the Sterling warranty.
DO NOT OVERCHARGE system. Overcharging results in
higher discharge pressure with higher cooling fluid con-
sumption, possible compressor damage, and higher power
consumption.
SUCTION ACCESS PORT
Fig. 20 — Suction Access Port