York YK-EP, Operation And Maintenance Manual

Page: 68 / 268

Table 54: Programmable
Button Access level Description
High Limit –
0.5 to 1.2VDC; default 0.6VDC
Specifies the Stall Detector Board output voltage that represents an
acceptable amount of stall noise.
The minimum difference between the High Limit Setpoint and the
Low Limit Setpoint is 0.1VDC. 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.
Low Limit –
0.3 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.
The minimum difference between the High Limit Setpoint and the
Low Limit Setpoint is 0.1VDC. 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 Admin Allows the user to clear the VGD Cycle Count.
Extreme Stall
Duration
–
10 to 20 minutes; default 10
Specifies the maximum 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 Open Pulse
Setpoint. While this is in effect, PRV Position Override is displayed as
Control Status.
Table 55: Navigation
Button Access Level Description
Home Service Returns user to HOME Screen.
VGD Screen Service Returns user to VARIABLE GEOMETRY DIFFUSER Screen
YK-EP Style B Centrifugal Chiller 68