Main Compressor Screen - York YD Mod D Operation Manual

Main compressor screen

Figure 10: Main compressor screen
This screen displays a cutaway of the chiller compressors, revealing the impellers. Animation of
the impeller indicates when the compressor is running. Several compressor related conditions are
shown. This screen also serves as a gateway to subscreens for Capacity Control, Surge protection
and the Oil Sump.
Table 16: Display only fields
Field/LED name
Oil sump temperature
System oil return solenoid (LED)
HGBP command
Lead compressor
Compressor 1: Oil pressure
40
Description
Displays the temperature of the oil in the Sump.
Lights when the solenoid is energized.
Displays the value of the Hot Gas Bypass Valve command over the range of 0%
(closed) to 100% (fully open). Only displayed if Hot Gas Bypass feature has been
enabled on the Operations screen.
Displays which compressor has been selected as the lead compressor. The lead
compressor is selected upon receipt of a start signal. The compressor that has the
least amount of run time that is ready to run is selected as the lead compressor.
Displays the pressure differential between the Pump Oil Pressure transducer for
compressor #1 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 compressor #1 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. However, 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 compressor #2 is already running when bringing compressor #1 online, the offset
calculation used will be that which was calculated during compressor #2 pre-lube.
Model YD Mod D with OptiView Control Center