Trane R Series Installation Operation & Maintenance page 65

RLC-SVX02G-E4
Maintenance Procedures
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
• Evaporator Liquid Level higher
than centerline after shutdown
• Very erratic liquid-level control
• Low unit capacity
• Low discharge superheat
(especially at high loads)
• Compressor rattle or grinding
sound
• High oil-sump level after normal
shutdown
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
shutdown
• Lower-than-normal oil
concentrations in the evaporator
R134a Field-Charging Procedure
Be certain that the electrical power
to the unit is disconnected before
performing this procedure.
WARNING
Position all electrical disconnects in
the "Open" position and lock them
to prevent injury or death due to
electrocution.
Follow the following procedure
when the unit is empty of all
refrigerant and under a vacuum.
Add the charge through the
evaporator service valve.
CAUTION
Water must be flowing through the
evaporator during the entire
charging process to avoid freezing
and rupturing of the evaporator
tubes.
1. Note the weight of the amount of
charge removed. Compare it to
General Data tables. A difference
in charge may indicate a leak.
2. Attach the charging hose to the
evaporator service valve (3/8"
[9 mm] flare). Open the service
valve.
3. Add charge to the evaporator to
bring the total circuit charge up to
the level indicated in the above
chart.
4. Close the service valve and
disconnect the charging hose.
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