AEC ACOA Series Air-Cooled Central Chillers - Manual (Page 49)

To determine the proper refrigerant charge, check the amount of subcooling at design full load
conditions. The amount of subcooling at the liquid line (liquid line saturation temperature
corresponding to liquid line pressure minus liquid line temperature) should be between 15ºF and
20ºF (-9ºC and -6ºC).
Subcooling at the condenser out-subcooler inlet trap should not exceed 5ºF (-15ºC). The sight
glass should be clear with no bubbles.
7-9 Preventive Maintenance Service
Following a systematic preventive maintenance program helps you avoid costly down time. Call
the Application Engineering Service Department at AEC, Inc. to arrange a schedule of
inspections.
This service, described in AEC, Inc. Bulletin No. 10-106.3, is tailored to fit your maintenance
requirements. Inspections include:
Check refrigerant suction and discharge pressures.
Check safety and operating controls.
Check voltage and amperage of all motors.
Check all electrical connections.
Check quantity of refrigerant.
Check compressor oil level.
Check lubrication of motor and pump bearings.
Check circulating pump operation.
Check flow through heat exchangers.
Check compressor efficiency.
Check noise levels.
Check cleanliness of equipment area.
Page 48
ACOA Series Air-Cooled Central Chillers