Specifications

10
MOTOR COOLING CYCLE
One half of the motor is cooled by suction gas while the
other half is cooled by liquid refrigerant taken from the bottom
of the condenser vessel. The flow of liquid refrigerant is main-
tained by the pressure differential that exists due to compressor
operation. The refrigerant flows through an isolation valve,
in-line filter/drier, and a sight glass/moisture indicator
(dry-eye), into the motor through the motor spray nozzle. See
Fig. 6 or 7.
The motor spray nozzle is orificed to control refrigerant
flow through the gaps between the rotor and stator. The refrig-
erant collects in the bottom of the motor casing and then drains
into the cooler through the motor cooling drain line.
The motor is protected by a temperature sensor and a
temperature switch imbedded in the stator windings. COMP
MOTOR WINDING TEMP temperatures above the COMP
MOTOR TEMP OVERRIDE threshold (see Capacity Over-
ride section, page 36) will override the chilled liquid tempera-
ture capacity control to hold. If the motor temperature rises
10° F (5.5 C) above this threshold, the compressor will unload.
If the COMP MOTOR WINDING TEMP rises above the
220 F (104.4 C) safety limit, the compressor will shut down.
LUBRICATION CYCLE
Summary —
The 23XRV requires an oil pump. Oil flow is
provided by a magnetically coupled, motor-driven oil pump.
Oil flows through the oil filter into the compressor rotors and
bearings. The cycle is referred to as a “high side” oil system.
See Fig. 8.
Details — The oil system:
• lubricates the roller bearings which support the male
and female rotors, and the ball bearings of the 23XRV
compressor.
• lubricates the male and female rotors.
Oil is charged into the system through a hand valve located
on the bottom of the oil sump. Sight glasses on the oil sump
permit oil level observation. When the compressor is shut
down, an oil level should be visible in the oil sump sight glass.
During operation, the oil level should always be visible in the
strainer housing sight glass. Approximately 7.5 gal. (28.4 L) of
oil is charged into the sump.
Oil from the compressor bearing drain is drained directly
into the oil sump. Refrigerant is driven from the oil as it flows
around the oil sump heater and into the strainer housing. The
oil pump draws the oil through a strainer and forces it through
an oil filter.
VFD
REFRIGERANT
COOLING
SOLENOID
VALVE
VFD
REFRIGERANT
COOLING
ISOLATION
VALVE
VFD
REFRIGERANT
COOLING
ISOLATION
VALVE
HGBP
SOLENOID
VALVE
HGBP ISOLATION
VALVE (OPTIONAL)
COMPRESSOR
CONDENSER
FLOAT VALVE BUBBLER LINE
STRAINER
FILTER DRIER
FILTER
DRIER ISOLATION
VALVES
MOTOR
VFD
COLD
PLATE
COOLER
FLOAT VALVE
ECONOMIZER MUFFLER
FLASH
ECONOMIZER
ORIFICE
Fig. 7 — Refrigerant Flow Schematic (With Optional Flash Economizer)
a23-1622