York YK-EP Operation And Maintenance Manual page 43

Table 26: Display only fields
Field/LED
Access level
name
Oil Pressure
Oil Pump
Drive
Command
Frequency
Vane Motor
Switch (LED)
Oil Return
Solenoid
(LED)
Pre-Rotation
Vanes
Service
Control
Mode
Pre-Rotation
Vanes Open Service
(LED)
Pre-Rotation
Vanes Close Service
(LED)
Full Load
Service
Amps
YK-EP Style B Centrifugal Chiller
Description
Displays the pressure differential between the high side oil pressure
transducer (compressor bearing input) and the low side oil pressure
transducer (oil sump). The displayed value includes offset pressure
derived from auto-zeroing during the System Prelube. If either of
the transducers used to calculate this differential is out of range, the
display field will show XX.X.
The offset pressure is the pressure differential between the high
oil pressure (HOP) transducer and the low oil pressure (LOP)
transducer outputs during a three (3) second period beginning
–
ten (10) seconds into the System Prelube. During this time, the
transducers will be sensing the same pressure and their outputs
should indicate the same pressure. However, due to accuracy
tolerances in transducer design, differences can exist. Therefore
to compensate for differences between transducers and assure
differential pressure sensing accuracy, the offset pressure is
subtracted algebraically from the differential pressure. The offset
pressure calculation will not be performed if either transducer is out
of range. The offset value will be taken as 0 PSI in this instance.
Displays the electrical frequency of the Oil Pump Drive motor. The
– frequency will go up or down to match the pump motor output to
the required oil pressure.
– Illuminates when the vanes are completely closed.
– Illuminates when the solenoid is energized.
Indicates whether the vanes are under manual or automatic control.
Indicates whether the vanes are in the process of opening.
Indicates whether the vanes are in the process of closing.
Displays the motor current as a percentage of the Full Load Amps
(FLA) value.
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