Specifications

11
The filter housing is capable of being isolated by upstream
and downstream valves to permit filter replacement. An oil
pressure regulator valve directs excessive oil back into the oil
sump. Oil supplied to the compressor is monitored by an oil
pressure sensor. The OIL PRESSURE DELTA P is equal to the
difference between the oil pressure leaving the filter and the oil
sump pressure. It is read directly from the ICVC (International
Chiller Visual Controller) default screen.
Oil is supplied to the compressor through two separate
inlets. One inlet leads to the suction bearings, the other leads to
the discharge bearings. Most of the oil drains back into the
sump while a small amount is used to lubricate the rotors.
Rotor lubrication oil leaves the compressor mixed with the
compressed discharge refrigerant vapor.
The oil sump contains temperature and pressure sensors and
a 530 W oil heater. The oil sump is vented to the compressor
suction to minimize the amount of refrigerant absorbed by the
oil. The OIL SUMP TEMPERATURE is measured and dis-
played on the ICVC default screen and the COMPRESS
screen. The oil sump pressure is used to calculate the OIL
PRESSURE DELTA P.
Operating OIL PRESSURE DELTA P must be at least
18 psid (124 kPa) after the OIL PRESS VERIFY TIME has
elapsed. Under normal full load conditions, oil pressure is
typically 20 to 28 psid (138 to 193 kPa). If sufficient oil pres-
sure is not established or maintained the chiller will shut down.
An oil pressure delta P sensor fault will be declared if the OIL
PRESSURE DELTA P is not less than 4 psid (27.6 kPa) prior
to start-up.
Fig. 8 — Oil Flow Schematic
OIL REFRIGERANT OIL/REFRIGERANT MIXTURE
A23-1643
ISOLATION
VALVE
CONDENSER
STRAINER
MIST
ELIMINATOR
COOLER
SIGHT GLASS
OIL
HEATER
MIST ELIMINATOR
SERVICE
VALVE
OIL PUMP
ISOLATION
VALVE
PUMP
FILTER
OIL FILTER
ISOLATION
VALVE
ORIFICE
ACTUATED BALL
VALVE
SIGHT GLASS
SIGHT GLASS
VAPORIZER
EXTERNAL OIL HEATER
ISOLATION
VALVE
COMPRESSOR OIL
DRAIN
TO COMPRESSOR
SUCTION
COMPRESSOR
OIL SUPPLY
PRESSURE
REGULATOR
VALVE
OIL
SUMP