This is an automatic reset device and, when tripped, will
cause the OIL TEMP light to glow. The RESET button must
CEO50 thru 100. When the oil pump is started, the piston is
be pushed for restart.
forced back by oil pressure, compressing the spring and fill-
The compresssor is equipped with lubrication protection
ing the piston cavity with oil. When the pump stops, the spring
for coast down in the event of a power failure. This is ac-
pressure on the piston forces the oil out to the bearings.
complished by the use of a spring loaded piston in models
In model CE126 the compressor coast down lubrication is
supplied from a gravity feed lube reservoir.
HOT GAS BYPASS
The PHH heat recovery chillers are equipped with a hot gas
bypass system used to feed discharge gas directly into the
evaporator when the system load falls below 10% of the com-
pressor capacity.
Light load conditions are signaled by a thermostat (HGT)
sensing return water temperature entering the evaporator.
This thermostat energizes the hot gas solenoid (HGS). This
introduction of hot gas provides a stable refrigerant flow and
keeps the machine from short cycling under light load con-
ditions. It also prevents surge during heat recovery operation.
OPERATING THE CHILLER
The initial startup of the McQuay centrifugal chillers after all
installation is complete must be performed by a factory trained
McQuay Service technician.
The following procedures apply to normal daily operation
of the equipment, assuming that the chiller will be secured
during periods when the building is unoccupied. In cases of
continuous operation, the operator should make operational
checks on the equipment at least once each day.
PRELIMINARY CHECKS BEFORE STARTING
Prior to attempting to start the chiller, the operator should
make a series of routine checks of the equipment to assure
that all components are ready for operation.
1. Assure that power has been on to the oil heaters
since
shutdown.
An EXT FAIL light on will signal if power has
been interrupted and has been restored.
FIGURE 9. PEH079 CHILLER (REAR VIEW)
LEGEND
1.
Evaporator Pressure
Relief Valve
2. Chilled Water Connections
3. Oil Cooler Water Connections
4. Condenser Pressure Relief Valves
5. Oil Cooler
6. Oil Pump Assembly
7. Discharge Line Check Valve
8. Lube (Control Box)
9. Motor Cooling Feed Line
10. Compressor Motor Terminal Box
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