Freeze Protection - Trane RTWD Installation Operation & Maintenance

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
RLC-SVX14H-GB
Service and Maintenance
Refrigerant Filter Replacement Procedure
A dirty fi lter is indicated by a temperature gradient
across the fi lter, corresponding to a pressure drop. If the
temperature downstream of the fi lter is 2.2°C lower than
the upstream temperature, the fi lter 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 fi lter fl ange.
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 fi lter fl ange.
7. Remove old fi lter element.
8. Inspect replacement fi lter element and lubricate
o-ring with Trane OIL00048.
NOTE: Do not use mineral oil. It will contaminate the
system.
9. Install new fi lter element in fi lter housing.
10. Inspect fl ange gasket and replace if damaged.
11. Install fl ange and torque bolts to 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.
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