Installation and Maintenance Manual

Service and Maintenance
192 RLC-SVX09H-EN
• 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
• Evaporator liquid level higher than centerline after
shut down
• Larger than normal condenser approach temperatures
(entering condenser saturated temperature – leaving
condenser water temperature)
• Condenser pressure limit
• High pressure cutout diagnostic
• 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
• Erratic liquid level control
• Low unit capacity
• Low discharge superheat (especially at high loads)
• Low liquid level diagnostics
• High oil sump level after normal shut down
Some symptoms of an oil under-charged unit:
• Compressor rattle or grinding sound
• Lower than normal pressure drop through oil system
• Seized or welded compressors
• Low oil sump level after normal shut down
• Lower than normal oil concentrations in evaporator
Refrigerant Filter Replacement Procedure
A dirty filter is indicated by a temperature gradient across
the filter, corresponding to a pressure drop. If the
temperature downstream of the filter is 4°F (-15.5°C) lower
than the upstream temperature, the filter should be
replaced. A temperature drop can also indicate that the
unit is undercharged. Ensure proper subcooling before
taking temperature readings.
1. With the unit off, verify that the EXV is closed. Close
liquid line isolation valve.
2. Attach hose to service port on liquid line filter flange.
3. Evacuate refrigerant from liquid line and store.
4. Remove hose.
5. Depress schrader valve to equalize pressure in liquid
line with atmospheric pressure.
6. Remove bolts that retain filter flange.
7. Remove old filter element.
8. Inspect replacement filter element and lubricate o-ring
withTrane OIL00048.
Note: Do not use mineral oil. It will contaminate the
system.
9. Install new filter element in filter housing.
10. Inspect flange gasket and replace if damaged.
11. Install flange and torque bolts to 14-16 lb-ft (19-22 n-m).
12. Attach vacuum hose and evacuate liquid line.
13. Remove vacuum hose from liquid line and attach
charging hose.
14. Replace stored charge in liquid line.
15. Remove charging hose.
16. Open liquid line isolation valve.
Freeze Protection
For unit operation in a low temperature environment,
adequate protection measures must be taken against
freezing.