York YK Style H Operation Manual page 72

SECTION 2 - OPTIVIEW CONTROL CENTER INTRODUCTION
VGD Position
Shows the position of the VGD. 0 to 100% open.
Maximum VGD Position
Shows the maximum calculated value that the VGD
will be allowed to open for the present condition. (0 to
100%). Opening too far could cause surge.
Surge Avoidance Surge Detected (LED)
Illuminates momentarily when a surge is detected by
the Surge Protection feature. If equipped with a VSD
or MV VSD, these are only the surges detected while
the drive is running at maximum frequency.
ACC Surge Detected (LED)
Only displayed if equipped with a VSD or MV VSD.
Illuminates mo-mentarily when a surge is detected by
the ACC func-tion in the Microboard, while the drive
is running at less than maximum frequency.
Stall Count
Displays the number of times the Stall Detector Board
output voltage goes above the High Limit Setpoint.
The count can be reset with an ADMIN access level
password.
Stall Time ( __Days __Hrs __Min __Sec)
Displays the accumulated time the Stall Detector Board
output voltage is greater than the High Limit Setpoint
while the chiller is running.
VGD Control State
Displays the current state of the VGD control. The
states are: Stall Waiting, Probing, Stall Reacting, Surge
Reacting, Surge Waiting, Hot Gas Hold, Hot Gas Over-
ride, Sensor Failure Override, Extreme Stall Override,
Manual Hold, Manual Open, Manual Close.
PROGRAMMABLE
Extreme Stall Duration
(10 to 20 minutes; default 10) – Specifies the maxi-
mum allowed time an extreme stall condition can exist
before the VGD operation is disabled and driven to the
full open position to protect it from damage.
PRV VGD Inhibit
[40% - 100% default 100%; While the Pre-rotation
Vanes position is greater than this setpoint, extreme
stall conditions are not checked, the VGD control is
inhibited and the VGD is pulsed open according to the
72
Open Pulse Setpoint. While this is in effect, PRV Posi-
tion Override is displayed as Control Status.
PRV Offset
(0 to 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.
Surge React Time
(1 to 30 seconds; default 5) – Specifies the length of the
close pulse applied to the VGD in response to a surge.
Surge Wait Time
(0.5 to 5 minutes; default 3) – Specifies how long the
VGD control remains in the Surge Waiting state before
entering the Probing state.
Stall Wait Time
(0.5 to 5 minutes; default 3) – Specifies how long the
VGD control remains in the Stall Waiting state before
entering the Probing state.
Open Pulse
(1 to 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 to 1.2VDC; default 0.6VDC; Specifies the Stall
Detector Board output voltage that represents an ac-
ceptable amount of stall noise.
Low Limit
(0.4 to 0.8VDC; default 0.5VDC; In the Stall Reacting
State, the VGD is driven closed until the Stall Detector
Board output voltage decreases to this level.
NAVIGATION
Home
Access Level Required: SERVICE
Returns user to HOME Screen.
VGD
Access Level Required: SERVICE
Returns user to VARIABLE GEOMETRY DIFFUSER
Screen.
FORM 160.76-O2
issue date: 6/15/2015
JOHNsON CONtROLs