Hussmann Ingersoll Rand, User Manual

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Mechanical Design 6
Oil Monitoring with Enhanced Centrifugal Lubrication
The more difficult task was to develop a suitable monitoring system for the oil circuit. An oil
control sensor (4) has been developed, which is mounted directly into the pocket (2). It utilizes a
heated PTC element, which is cooled by the circulating oil. If the oil flow is interrupted
significantly, the PTC heats up, provides an alarm output and shuts the compressor off. This type
of compressor oil monitoring is as reliable as methods for the pump-lubricated version. The oil
sensor accounts for the risk of oil circulation failure caused by abnormal conditions that may
appear in certain circumstances, for example; multiple compressor racks with extended piping.
Monitoring of the internal lubrication system itself is of a certain minor significance since the
compressor has proven to be even more reliable due to this sophisticated system.
IR Impact
¥
C-Series compressors with Enhanced Centrifugal Lubrication require one of the
following oil loss safety controls:
- Traxon Traxoils
TM
- Thermal Oil Loss Sensor and Control Module
Oil Monitoring with Positive Displacement Lubrication
IR Impact
¥
B-Series and C-Series compressors with oil pumps may use one of several types of
oil controls. The “Delta-P” is an integrated oil sensor/switch that mounts directly on the
compressor housing (bearing cover) and does not require an external control module. A Johnson
Control P545 electronic oil safety switch may also be used and mounts in the same location as
the Delta-P. Finally, an externally mounted oil switch may be used with tubing connections to
the compressor suction and discharge of the oil pump. The following pages list technical
information for each type of control.
“Delta-P” Oil Differential Pressure Control Technical Data
Supply Voltage 230 VAC +/- 10%, 50/60 Hz, other
voltages on request
Power Consumption 10 VA
Time Delay with Low Oil Pressure 90 s
Control Relay 250 V max., 2 A max.
720 VA max. Inductive load
Fusing for device and switch contacts 6 A max.
Connecting Cable 4 x AWG20, 3 ft, color coded
Refrigerants All typical CFC’s, HCFC’s and HFC’s
Enclosure Class IP54
Differential Cutout Pressure 9.4 psi
Allowable operating temperature -22 to 140°F
Weight 0.44 lb
The oil pressure monitoring is activated when supply voltage is applied by way of an auxiliary
contact of the motor contactor. The red LED lights immediately to indicate low oil differential
pressure. Once oil pressure is established, the LED turns off. The output contact remains closed
if the oil differential pressure exceeds the cutout pressure.