Maintenance; Periodic Maintenance - Trane CGAM Installation & Operation Manual

Maintenance

Periodic Maintenance

General
Perform all maintenance procedures and inspection at the
recommended intervals.This will prolong the life of the
chiller and minimize the possibility of malfunctions.
Use an "Operator's Log" to record the unit's operating
history.The log serves as a valuable diagnostic tool for
service personnel. By observing trends in operating
conditions, an operator can anticipate and prevent
problem situations before they occur.
If the unit is not operating properly during maintenance
inspections, consult the "Diagnostic and
Troubleshooting" section of this manual.
Weekly Maintenance
Verify that compressor oil sump heaters are connected
tightly around the compressor.
After the chiller has been operating for approximately 30
minutes and the system has stabilized, check the operating
pressures and temperatures and complete the following
checks:
Check the evaporator and condenser refrigerant pressures
in the Refrigerant Report menu of the CH530 display.
Pressures are referenced at sea level (14.6960 psia).
Check the electronic expansion valve sight glasses. (Note:
The electronic expansion valve is commanded closed at
unit shutdown and if the unit is off, there will be no
refrigerant flow through the sight glasses. Only when a
circuit is running will refrigerant flow be present.)The
refrigerant flow through the sight glasses should be clear.
Bubbles in the refrigerant indicate either low refrigerant
charge or excessive pressure drop in the liquid line. A
restriction in the line can sometimes be identified by a
noticeable temperature differential between the two sides
of the restriction. Frost may often form on the liquid line at
this point. Correct refrigerant charges are shown in the
General DataTables.
Important: A clear sight glass alone does not mean that
the system is properly charged. Also check
the system superheat, subcooling and unit
operating pressures.
WARNING
R-410A Refrigerant under High Pressure!
Use ONLY R-410A rated service equipment or
components with these units. For specific handling
concerns with R-410A, please contact your local Trane
representative.
Failure to use R-410A rated service equipment or
components could result in equipment exploding under
R-410A high pressures which could result in death,
serious injury, or equipment damage.
CG-SVX17E-EN
NOTICE:
Compressor Damage!
Only add liquid in the suction line when the compressor
is running. Use extreme caution to meter liquid
refrigerant into the suction line slowly. If liquid is added
too rapidly, compressor oil dilution and oil pumpout
could occur. Failure to follow the above could result in
compressor failure or reduced compressor life.
Check the system superheat, subcooling, evaporator
temperature drop (Delta-T), evaporator water flow,
evaporator approach temperature, compressor discharge
superheat, condenser approach and compressor RLA.
Normal operating conditions at AHRI Conditions (55-44°,
95° ambient, .0001ffe) are:
• Evaporator Pressure: 120 psig
• Evaporator Approach: 5-10°F
• Evaporator Superheat: 12°F
• Electronic Expansion Valve: 40-50 percent open
• EvaporatorTemperature Drop (Delta-T): 10°F
• Compressor DischargeTemperature: 63°F or more
• Compressor SuctionTemperature: 20°F or more
• Condensing Pressure: 420-440 psig
• Condensing ApproachTemperature: 25°F
• System Subcooling: 15-20°F
• Compressor RLA: 100 percent
If operating pressures and sight glass conditions seem to
indicate a refrigerant shortage, measure the system
superheat and subcooling. Refer to "System Superheat"
and "System Subcooling. "
If operating conditions indicate a refrigerant overcharge,
remove refrigerant at the liquid line service valve. Allow
refrigerant to escape slowly to minimize oil loss. Use a
refrigerant recovery cylinder and do not discharge
refrigerant into the atmosphere.
CAUTION
Refrigerant at Freezing Temperature!
Avoid contact with skin. If working with refrigerant is
necessary, you MUST wear all Personal Protective
Equipment (PPE) including eye protection, safety
gloves, long sleeves, and pants. In case of contact, treat
the injury similar to frostbite. Slowly warm the affected
area with lukewarm water and seek immediate medical
attention. Direct contact with liquid refrigerant could
result in minor to moderate injury.
Inspect the entire system for unusual conditions and
inspect the condenser coils for dirt and debris. If the coils
are dirty, refer to "Coil Cleaning" in this manual.
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