CG-SVX17D-EN 163
Maintenance
Compressor Oil Sump Heaters
Compressor oil sump heaters must be energized at least 24 hours before starting the CGAM chiller.
This is required to boil refrigerant out of the oil before startup. Ambient temperature is not a factor
and the oil sump heaters must always be energized prior to startup.
Condenser Maintenance
Condenser Coil Cleaning
Clean the condenser coils at least once a year or more frequently if the unit is in a “dirty”
environment. A clean condenser coil will help to maintain chiller operating efficiency. Follow the
detergent manufacturer's instructions to avoid damaging the condenser coils.
To clean the condenser coils use a soft brush and a sprayer such as a garden pump type or a high-
pressure type. A high quality detergent such as Trane Coil Cleaner (Part No. CHM-0002) is
recommended.
Note: If detergent mixture is strongly alkaline (pH value greater than 8.5, an inhibitor must be
added).
Evaporator Maintenance
NOTICE:
Equipment Damage!
The factory-installed immersion heater must be de-energized if the BPHE evaporator is drained
of water for any reason. Failure to de-energize the immersion heater will cause it to burn out.
The Trane Model CGAM liquid chiller uses a brazed plate heat exchanger (BPHE) evaporator with
factory-installed electronic flow switch (IFM efector) that is positioned in the evaporator water pipe.
The evaporator inlet also includes a factory-installed immersion heater for freeze protection and
a water strainer that must be kept in place to keep debris out of the evaporator.
Note: Strainer maintenance is critical to proper operation and reliability. Any particles larger than
1mm entering the BPHE evaporator may cause the evaporator to fail, requiring
replacement.
Acceptable BPHE evaporator water flow rate is 1.5 to 3.6 GPM per nominal unit ton capacity. To
maintain 54-44 F in/out chilled water temperatures, the nominal water flow rate is 2.4 GPM per ton.
Minimum water flow rate must be maintained to avoid laminar flow, potential evaporator freezing,
scaling and poor temperature control. The microprocessor and capacity control algorithms are
designed to take a 10 percent change in water flow rate per minute while maintaining a ±2°F (1.1°C)
leaving water temperature control accuracy. The chiller tolerates up to 30 percent per minute water
flow variation as long as the flow is equal to or greater than minimum flow requirements.
Maximum water flow is 18 feet per second. Flow rates greater than this will cause excessive
erosion.
The BPHE evaporator is difficult to clean should it become plugged with debris. Indications of a
plugged BPHE evaporator include “wet” suction due to lack of heat exchange, loss of superheat
control, depressed discharge superheat (superheat less than 63°F), compressor oil dilution and/or
starvation and premature compressor failure.
Evaporator Replacement
If the CGAM evaporator requires replacement, it is very important that the new evaporator be
replaced correctly and with the correct refrigerant and water piping connections. The refrigerant
inlet/liquid connection is at the bottom of the evaporator and the refrigerant outlet/suction
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