York YD Mod D, Operation Manual, Page: 42 / 160

Compressor 1 or 2 screen
Figure 11: Compressor 1 screen
This screen displays a cutaway of the compressor #1 or #2, revealing the impeller. Animation of
the impeller indicates when the compressor is running. Parameters related to the compressor are
displayed here. Also, compressor manual control functions are performed here. The Pre-rotation
Vanes and Discharge Valve can be manually controlled. This screen also serves as a gateway to
subscreens to calibrate the Pre-rotation vanes and Proximity Probe.
Note: Requires login access level of SERVICE.
Table 18: Display only fields
Field/LED name Description
Oil pressure
Displays the pressure differential between the Pump Oil Pressure transducer for
the compressor and the common Sump oil pressure transducer. If either of these
transducers are out of range, the display field will show XX.X psid. The displayed value
includes the offset pressure derived from auto-zeroing during the system pre-lube
period. The offset pressure is the pressure differential between the compressor Pump
Oil Pressure Transducer and the Sump Oil Pressure transducer outputs during a 3-
second period beginning 10 seconds into the system pre-lube period. During this time,
the transducers are sensing the same pressure and their outputs should indicate the
same pressure. As a result, due to accuracy tolerances in transducers, 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 is not performed if
either transducer is out of range. The offset value is taken as 0 psi in this instance.
If one compressor is already running when bringing on the second compressor, the
offset calculation used will be that which was calculated during the first compressor
pre-lube.
Oil sump temperature Displays the temperature of the oil sump.
Discharge temperature Displays the discharge temperature.
High speed thrust bearing proximity
differential
Displays the distance between the high speed thrust collar and the tip of the Proximity
Probe for compressor #1. This measurement takes into account the reference position
established at the time of chiller manufacture.
HGBP command
Indicates the Hot Gas Bypass Command 0% (Closed to 100% (Open). Only displayed if
Hot Gas option is installed and enabled on the Operations screen.
Model YD Mod D with OptiView Control Center 42