FORM 160.87-OM1
ISSUE DATE: 8/24/2018
JOHNSON CONTROLS
60
SECTION 2 - OPTIVIEW CONTROL CENTER INTRODUCTION
ECONOMIZER COMPRESSOR VARIABLE GEOMETRY DIFFUSER SCREEN
FIGURE 22 -
ECONOMIZER COMPRESSOR VGD SCREEN
OVERVIEW
This screen displays information pertinent to the Econ-
omizer VGD operation. Also, the Economizer VGD
can be manually controlled from this screen.
DISPLAY ONLY
Stall Detector Voltage
Displays the Stall Detector output voltage as received
by the Microboard.
High Limit
Displays the voltage, that if exceeded, will result in the
VGD closing to prevent a stall from occurring.
Low Limit
Displays the voltage, that if has dropped below the
setpoint, will cause the VGD to open, allowing more
gas through the compressor.
Mach Number
Displays the speed of the refrigerant gas leaving the
compressor in percentage of Mach (the speed of sound).
VGD Closed Limit Switch
Displays the status of the VGD Limit Switch. Dis-
played as CLOSED when the switch is closed. This
would be when the VGD is in the fully closed position.
Otherwise, displayed as OPEN.
VGD Opening (LED)
Illuminates when a close signal is being applied to the
VGD.
VGD Closing (LED)
Illuminates when an open signal is being applied to the
VGD.
Stall Count
Displays the number of times that the system had de-
tected an Economizer Compressor Stall.
Stall Time
Displays the accumulated time that the Stall Detector
Board output is greater than the High Limit Setpoint
voltage while the chiller is running.
LD19633
