Compressor Screen; Figure 10 - Compressor Screen - York YR Manual

Optiview Control Center
SECTION 2 - OPTIVIEW™ CONTROL CENTER

FIGURE 10 - COMPRESSOR SCREEN

Overview
This screen displays a cutaway view of the chiller com-
pressor, revealing the rotary screw, and shows all con-
ditions associated with the compressor. The slide valve
positioning is animated and with the proper Access
Level it can be manually controlled. Animation of the
compressor rotors indicates whether the chiller is pres-
ently in a RUN condition. This screen also serves as a
gateway to sub-screens for calibrating the slide valve
or configuring the optional Hot Gas Bypass.
Display Only
Differential Oil Pressure
Displays the pressure differential between the oil
pressure transducer (input to the compressor) and the
Evaporator Pressure Transducer. The displayed value
includes the offset pressure derived from auto-zeroing
during the Start Sequence Initiated. If either of the
transducers used to calculate this differential is out of
range, the display field will show XX.X.
Differential Oil Pressure = (Oil Pressure - Evaporator
Pressure) + Offset Pressure
The Offset Pressure is used to calculate the differential
pressure. The Offset Pressure is the pressure differen-
tial between the oil pressure transducer and the Evapo-
rator Pressure Transducer during the first 15 seconds of
Start Sequence Initiated. This is the transducer auto-ze-
roing. During this time the transducers will be sensing
36

COMPRESSOR SCREEN

the same pressure and their outputs should be equal.
However, due to accuracy tolerances in transducer de-
sign, differences can exist. Therefore, to compensate
for differences between transducers and assure differ-
ential pressure sensing accuracy, the Offset Pressure is
subtracted from or added to the differential pressure.
(Certain operating conditions could require the auto-
zeroing to be disabled. This must never be done by
anyone other than a qualified service technician). The
offset pressure calculation will not be performed if ei-
ther transducer is out of range. The offset value will be
taken as 0 PSI in this instance.
Discharge Pressure
Displays the pressure at the discharge of the compressor.
Discharge Temperature
Displays the temperature of the refrigerant in its gas-
eous state at discharge of the compressor as it travels
to the Oil Separator.
Discharge Superheat
In software versions C.MLM.05.04.xxx (and later),
displayed value is Discharge Temperature minus Dis-
charge Saturation Temperature. Discharge Saturation
Temperature is not a displayed value. In earlier ver-
sions, it is Discharge Temperature minus Condenser
Saturation Temperature.
FORM 160.81-O1 (1020)
ISSUE DATE 10/05/2020
LD09717
JOHNSON CONTROLS