Periodic Maintenance - Trane SINTESIS ADVANTAGE CGAF Series Installation Operation & Maintenance

Periodic Maintenance

General
Perform all maintenance procedures and inspections at
the recommended intervals. This will increase the life of
the chiller and minimize the possibility of serious and
costly breakdown.
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. Proper servicing of the service valves is
required. Use a backup wrench as shown in Figure when
loosening or tightening the service valve cap.
Figure 28 – Servicing of service valves
Weekly Maintenance
After the unit has been operating for approximately
30 minutes and the system has stabilized, check the
operating conditions and complete the procedures
below:
1. Check on the TD7 pressure for evaporator,
condenser, and intermediate oil.
Note: Pressures are referenced at sea level.
2. 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.
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 is shown in nameplate.
74
NOTICE: A clear sight glass alone does not mean that
the system is properly charged. Also check the system
superheat, sub cooling and unit operating pressures.
NOTICE: Use only manifold gauge sets designed for use
with R410A refrigerant.
Use only recovery units and cylinders designed for the
higher pressure of R410A refrigerant and POE oil.
NOTICE: R410A must be charged in a liquid state.
Check the system superheat, subcooling, evaporator
temperature drop (Delta-T), evaporator water flow,
evaporator approach temperature, compressor discharge
superheat, and compressor RLA.
Normal operating conditions at ISO conditions are:
Evaporator pressure: 8 bars
Evaporator Approach: 3-5°C
Evaporator Superheat: 6-7°C
Note: In Case of Optional Service valve with CXAF ,
ensure the re-opening of the oil return valve (Item
13 in Refrigerant system schematic & Oil lube circuit
schematic for CXAF – BPHE) after refrigerant transfer.
Note: If the superheat is unstable, check the suction
temperature sensor. The suction temperature sensor
should be well inserted into the well and thermal grease
should be used to ensure a good contact between the
sensor and the well.
Electronic Expansion Valve: 30-50 percent open
Evaporator Temperature Drop (Delta-T): 5°C
Condensing Pressure: 28-32 bars
Condensing Approach Temperature: 14-18°C
System Subcooling: 8-12°C
If operating pressures and sight glass conditions seem
to indicate a refrigerant shortage, measure the system
superheat and sub cooling.
Refer to "System Superheat" and "System Sub cooling. "
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.
WARNING! Do not allow refrigerant to directly contact
skin as injury from frostbite may result.
CG-SVX039C-GB