Trane RTUB 207-224 - Manual (Page 27)

27
Follow the steps listed below and
refer to the notes listed in Figure 17.
1. Turn off the unit.
2. Attach the hoses and sight glass to
the oil-separator Schrader valves,
as shown in Figure 17. Remove
non-condensables.
3. After the unit has been off for
10 minutes, move the sight glass
up and down until the level can be
seen.
4. After the level has been
determined, remove the sight
glass and hoses.
Refrigerant and Oil-Charge
Management
Proper oil and refrigerant charge is
essential for proper unit operation,
unit performance, and
environmental protection. Only
trained and licensed service personal
should service the unit.
Some symptoms of a refrigerant
under-charged unit:
• Low subcooling
• Larger-than-normal evaporator
approach temperatures (Leaving-
Water Temperature - Saturated
Evaporator Temperature)
• Low Evaporator-Refrigerant
Temperature Limit
• Low Refrigerant-Temperature
Cutout diagnostic
• Fully-open expansion valve
• Possible whistling sound coming
from liquid line (due to high vapor
velocity)
• High Condenser + Subcooler
Pressure drop
Some symptoms of a refrigerant
over-charged unit:
• High subcooling
• Larger-than-normal condenser
approach temperatures (Entering-
Condenser Saturated Temperature -
Entering-Air Temperature)
• Condenser Pressure Limit
• High-Pressure Cutout diagnostic
• More-than-normal number of fans
running
• Erratic fan control
• Higher-than-normal compressor
power
• Very low discharge superheat at
startup
• Compressor rattle or grinding
sound at startup
Some 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
• Compressor rattle or grinding
sound
• High oil-sump level after normal
shutdown
Checking the separator oil
level
Figure 17 - System Oil Specifications
1 Oil separator
2 Valve
3 ¼" refrigeration hose
4 Sight glass
5 Minimum oil level
6 Maximum oil level
Table 5 - Oil level limit
Oil separator diameter (mm)
152 203 254
Minimum oil level (mm) 90 120 145
Maximum oil level (mm) 155 205 235
Maintenance
RLC-SVX03A-E4