York YST Operation Manual page 42

SECTION 2 - OPTIVIEW CONTROL CENTER INTRODUCTION
Stall dC pressure voltage
Displays the DC voltage from the stall pressure trans-
ducer.
Time remaining
While the VGD is in the Stall Waiting State, displays
the time remaining in the "Probe Wait Time" interval
(value programmed as the Probe Wait Time Setpoint).
prograMMable
prv offset
(0-5%; default 3) – If the VGD control is in the Stall
Waiting state and the Pre-rotation vanes position
changes by more than this value, the Probing state will
be entered. If the PRV Offset is set to 0%, the Stall
Waiting state is performed based only on the "Probe
Wait Time" setpoint interval.
probe Wait
(0.5-15 minutes; default 10) – Specifies how long the
VGD control remains in the Stall Waiting or Surge
Waiting states before entering the Probing state.
open pulse
(1-9 seconds; default 2) – Specifies the length of the
open pulse applied to the VGD during 10 second peri-
ods while in the Probing state.
high limit
(0.5-1.2Vdc; default 0.8) – Specifies the Stall Detec-
tor Board output voltage that represents an acceptable
amount of stall noise.
extreme Stall duration
(1-20 Min, default 10) – If the Stall Detector Volt-
age exceeds twice the High Limit for this duration,
the VGD control is disabled, the VGD is opened, and
WARNING – CONDITIONS OVERRIDE VGD is
displayed.
42
prv vgd inhibit
(40-100%, default 95) – If the Pre-Rotation Vanes Po-
sition is above this value, the VGD control is disabled
and the VGD is pulsed open according to the Open
Pulse setpoint.
low limit
(0.4-0.8vdc; default 0.6) – in the Stall Reacting State,
the VGD is driven closed until the Stall Detector Board
output voltage decreases to this level.
The minimum difference between the High Limit
setpoint and the Low Limit setpoint is 0.1 vdc. If a
Low Limit setpoint is entered which is less than 0.1vdc
below the High Limit setpoint, the High Limit setpoint
is adjusted so that it is 0.1vdc above the newly entered
Low Limit value.
vgd Count
Access Level required: ADMIN
Allows the user to clear the VGD Cycle Count.
navigaTion
home
Access Level Required: SERVICE
Causes an instant return to the Home Screen.
vgd Screen
Access Level Required: SERVICE
Causes an instant return to the Variable Geometry Dif-
fuser Screen.
FORM 160.67-O1
ISSUE DATE: 4/1/2015
JOHNSON CONTROLS