AEC ACOA Series Air-Cooled Central Chillers - Manual (Page 47)

When using chemicals for cleaning, pump a caustic solution through the heat exchanger. The
chemicals attack dirt, slime, and mineral deposits and flushes them away. Water treatment
specialists can recommend appropriate chemicals.
Rinse the system thoroughly after cleaning to remove the chemicals before they attack the metal
surfaces. You cannot be physically clean the evaporator side because of the cross-flow baffle
construction.
7-5 Cleaning Air Cooled Condensers
Clean the face of the condenser at least once a month during operation. If conditions are bad
and condensers pick up dirt very quickly, clean them more frequently. If you allow the condenser
to get too dirty, the unit runs a high head pressure and does not provide satisfactory performance.
Clean dirty coils with a soft brush, by flushing with cool water, or by using commercially-
available coil cleaners. Do not use hot water or steam. Doing so causes excessive pressure in
the system. Clean the face of the condenser at the beginning of the season and periodically
thereafter as conditions require.
7-6 Protections Against Electrical Malfunctions
The unit has four devices designed to protect compressor motors and manual motor controllers
from electrical malfunction:
• Circuit breakers
• Starter overload relays
• Under voltage relay (optional)
• Motor over temperature protectors
If the undervoltage relay trips, it is a sign of trouble in incoming power. If it trips again after
resetting, call your electric utility to investigate the problem. If circuit breaker or motor overload
relay or motor overtemperature protectors trip, it is a sign of possible motor trouble. DO NOT
reset and try to run compressor again. Call an authorized service representative to check for
motor trouble. Resetting these safety devices and then starting the unit repeatedly could turn a
minor motor problem into a costly major motor burnout.
7-7 Maintaining Compressors
Discus compressors have four components you can replace: the suction strainer, oil pump,
cylinder heads, and valve plates.
Page 46
ACOA Series Air-Cooled Central Chillers