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Maintenance
the compressor connection has been unsweated.The line
can then be reinstalled using a slip coupling and brazing.
NOTICE:
Equipment Damage!
The compressor suction line configuration must not be
changed in any way. Changing compressor suction line
configuration will compromise proper oil return to the
compressor(s).
Compressor Electrical Terminal Box
Be sure to protect the terminal box when unbrazing or
brazing compressor refrigerant piping connections
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
WARNING
Hazardous Chemicals!
Coil cleaning agents can be either acidic or highly
alkaline and can burn severely if contact with skin
occurs. Handle chemical carefully and avoid contact
with skin. ALWAYS wear Personal Protective Equipment
(PPE) including goggles or face shield, chemical
resistant gloves, boots, apron or suit as required. For
personal safety refer to the cleaning agent
manufacturer's Materials Safety Data Sheet and follow
all recommended safe handling practices. Failure to
follow all safety instructions could result in death or
serious injury.
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 asTrane Coil Cleaner (Part No.
CHM-00255) is recommended.
Refer to RTAC-SVG01B-EN for maintenance and cleaning
procedures.
Note: If detergent mixture is strongly alkaline (pH value
greater than 8.5, an inhibitor must be added).
136
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.
TheTrane 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 (<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 connection is at the top of the evaporator and both
are on the same side. Pay particular attention to
evaporators with dual circuits. Avoid cross-circuiting
when installing the new evaporator.
CG-SVX17E-EN
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