Trane SINTESIS ADVANTAGE CGAF Series Installation Operation & Maintenance page 76

Periodic Maintenance
Refrigerant and Oil-charge
Management
Proper oil and refrigerant charge is essential for proper
unit operation, unit performances, and environmental
protection. Only trained and licensed service personnel
should service the chiller.
Some of the symptoms of a refrigerant under-charged
unit:
• Larger-than-normal evaporator approach temperatures
(leaving water temperature – saturated evaporator
temperature). If the refrigerant charge is correct the
approach temperature is 4°C. These values are given
for units running at full load and with water without
antifreeze
• Low Evaporator-refrigerant temperature limit
• Low Refrigerant-Temperature cutout diagnostic
• Fully-open expansion valve
• Possible whistling sound coming from liquid line
(due to high vapour velocity)
• High condenser + Sub cooler pressure drop
Some of the symptoms of a refrigerant over-charged unit
• Condenser Pressure Limit
• High –Pressure Cutout diagnostic
• More-than-normal number of fans running
• Erratic fan control
• Higher-than-normal compressor power
Some of the symptoms of an oil over-charged unit
• Larger-than-normal evaporator approach temperatures
(Leaving-water-temperature – Saturated Evaporator
Temperature)
• Low Evaporator-refrigerant Temperature limit
• Low Refrigerant – Temperature Cutout diagnostic
• Low unit capacity
• High oil-sump level after normal shutdown
• Discharge temperature is lower than prediction
provided by compressor manufacturer selection
program.
Some of the symptoms of an oil under-charged unit
• Seized or Welded compressors
• Low oil-sump level after normal shutdown
76 CG-SVX039C-GB