Installation and Maintenance Manual

RTWD/RTUD Operating Principles
RLC-SVX09H-EN 129
Oil System Operation (RTWD/RTUD)
Overview
Oil that collects in the bottom of the oil separator is at
condensing pressure during compressor operation;
therefore, oil is constantly moving to lower pressure areas.
As the oil leaves the separator, it passes through the oil
cooler (if installed). It then goes through the service valve
and filter. At this point it travels through the oil control
valve.Then it provides oil injection and bearing
lubrication.
If the compressor stops for any reason, the oil control
valve closes, isolating the oil charge in the separator and
oil cooler during off periods.The master oil valve is a
pressure activated valve. Discharge pressure off the
rotors, that is developed when the compressor is on,
causes the valve to open.
Compressor Motor
A two-pole, hermetic, induction motor (3600 rpm at 60 hz,
3000 rpm at 50hz) directly drives the compressor rotors.
The motor is cooled by suction refrigerant gas from the
evaporator, entering the end of the motor housing through
the suction line.
Compressor Rotors
Each compressor has two rotors - “male” and “female” -
which provide compression. See Figure 51, p. 130 .The
male rotor is attached to, and driven by, the motor, and the
female rotor is, in turn, driven by the male rotor.
Separately housed bearing sets are provided at each end
of both rotors.
Figure 50. RTWD/RTUD oil system
EXV
Evaporator
Manual
Service
Valve
Oil Cooler
(optional on RTWD)
Compressor
Oil
Separator
Gas Pump
Oil Return System
Bearing and Rotor
Restrictors and
Oil injection
Condenser
Condenser
Refrigerant
Pressure
Transduce r
P
C
Oil Pressure
Transduce r
Po
Evaporator
Refrigerant
Pressure
Transduce r
P
E
Primary Oil System
Refrigerant & Oil Mixture
(refrigerant vapor and oil)
Oil Recovery System
(liquid refrigerant and oil)
Refrigerant with
small amount of Oil
KEY
Compressor Discharge
Temperature Sensor
Internal
Compressor
Oil Filter
Oil Separator
Sump Heater
Compressor
Heater
Optical Oil Eye