Motor And Oil Cooling Cycle - Carrier AquaEdge 19XR series Start-Up, Operation And Maintenance Instructions Manual

ISOLATION
VALVE
MOISTURE/
FILTER
FLOW
DRIER
INDICATOR
ROTOR
ORIFICE
FITTING
THERMOSTATIC
EXPANSION
VALVE (TXV)
ORIFICE
OPTIONAL UNIT
MOUNTED VFD
(VARIABLE
FREQUENCY
DRIVE) HEAT
EXCHANGER
Fig. 5 — Refrigeration Cycle — 19XR,XRV Two-Stage Compressor

MOTOR AND OIL COOLING CYCLE

The motor and the lubricating oil are cooled by liquid refriger-
ant taken from the bottom of the condenser vessel (Fig. 4 and
5). Refrigerant flow is maintained by the pressure differential
that exists due to compressor operation. After the refrigerant
flows past an isolation valve, an in-line filter, and a sight glass/
moisture indicator, the flow is split between the motor cooling
and oil cooling systems.
REFRIGERANT
COOLING
ISOLATION
VALVE
ORIFICE
FITTING
TRANSMISSION
MOTOR
IMPELLERS
COMPRESSOR
OIL COOLER
BACK PRESSURE
ORIFICE (INTEGRAL
TO MOTOR SHELL)
COOLER
ISOLATION
VALVE
(OPTION)
FLASC CHAMBER
FLOAT
VALVE
CHAMBER
HOT GAS BYPASS (OPTIONAL)
DAMPER
VALVE
HGBP VALVE
REFRIGERANT
ISOLATION VALVE
FLOAT BALL VALVE
IMPORTANT: To avoid adverse effects on chiller opera-
tion, considerations must be made to condenser water tem-
perature control. For steady state operation, the minimum
operating refrigerant pressure differential between cooler
and condenser is approximately 20 psi (138 kPa) with a
maximum evaporator refrigerant temperature of 65 F
(18 C). Consult Chiller Builder for required steady state
operational limits. Inverted start conditions are acceptable
for short durations of time, but for periods exceeding 5
minutes, a special control solution strategy should be used
to allow the chiller to establish a minimum refrigerant pres-
sure differential (and thereby adequate equipment cooling).
11
CONDENSER
WATER
REFRIGERANT
LIQUID
REFRIGERANT
VAPOR
REFRIGERANT
LIQUID/VAPOR
CHILLED
WATER