Refrigerant Filter Replacement Procedure; Lubrication System; Oil Charging Procedure - Trane R Series Installation, Operation And Maintenance Manual

Maintenance
charge in the condenser. It may be connected to the
condenser drain port on the liquid line isolation valve.
Notes: If a pump is to be used, connect it before closing
this valve.This port is only isolated when the
valve is back seated.If a vacuum pump is used,
connect it to the discharge line service valve near
the oil separator. A vacuum pump will be
required for part of the procedure.
The evaporator is large enough to hold all the charge for
any unit to below the centerline of the shell.Therefore, no
special precautions are required to restart the unit after
isolating the charge in the 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 8°F (4.4°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. On units with remote
evaporators or oil cooling circuits, close ball valve on
oil cooler liquid line.
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. On units with remote
evaporators or oil cooler circuits, open oil cooler liquid
line ball valve.
RTAC-SVX01J-EN

Lubrication System

The lubrication system has been designed to keep most of
the oil lines filled with oil as long as there is a proper oil
level in the oil sump.
The total oil charge can be removed by draining the oil
system, oil return line from the evaporator, the evaporator,
and the compressor. Very small quantities of oil may be
found in other components.
Like many machines, an excessive oil charge can cause
operational problems. Special care should always be
taken to avoid adding extra oil.
Units that exhibit the symptoms of an oil overcharge at
high loads may still run fine at light loads. An oil
overcharged unit may result in an evaporator limit
warning or even a low liquid level or low evap temp (LRTC)
diagnostic. An oil overcharged unit may exhibit increased
approach temperatures and decreased overall unit
efficiency.

Oil Charging Procedure

Proper charging of the oil system is critical to the reliability
of the compressor and chiller.Too little oil can cause the
compressor to run hot and inefficient. When taken to an
extreme, low oil level may result in instant failure of the
compressor.Too much oil will result in high oil circulation
rates which will foul the condenser and evaporator
performance.This will result in inefficient operation of the
chiller.Taken to an extreme, high oil levels may result in
erratic expansion valve control or shut down of the chiller
due to low evaporator refrigerant temperature.Too much
oil may contribute to long term bearing wear. Additionally,
excessive compressor wear is probable when the
compressor is started with the oil lines dry.
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