York YD Mod D, Operation Manual, Page: 50 / 160

Table 31: Programmable
Button Access level Description
PRV VGD inhibit Service
(40% to 100%; default 90%). Applicable to dual compressor operation only. Both
VGD’s will be pulsed open according to the OPEN PULSE Setpoint as long as both
compressor’s PRV’s are above this value. While this is in effect, “PRV Position
Override” is displayed as Control Status.
PRV offset Service
(0%-5%; default 3%) – This setpoint applies to both VGD controls. 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 Service
(1-30 seconds; default 5) – This setpoint applies to both VGD controls. Specifies the
length of the close pulse applied to the VGD in response to a surge.
Probe wait Service
(0.5-15 minutes; default 10) – This setpoint applies to both VGD controls. Specifies
how long the VGD control remains in the Stall Waiting or Surge Waiting states before
entering the Probing state.
Open pulse Service
(1-5 seconds; default 2) – This setpoint applies to both VGD controls. Specifies the
length of the open pulse applied to the VGD during 10 second periods while in the
Probing state.
Override delta Service
(1% to 10%; default 5%) - This setpoint applies to both VGD controls. This setpoint
specifies the maximum allowed difference (1% to 10%) between the Lead VGD position
and the Lag VGD position while the VGD Position Override is in effect. The override
starts when the lag compressor pre-rotation vanes position is greater than or equal to
80% of the lead compressor pre-rotation vanes. While this override is in effect, if the
difference between the Lead VGD position and the Lag VGD position is greater than
the Override Delta setpoint, the VGD with the higher position is driven closed until it is
within the allowed difference. “VGD Position Override” is displayed as Control Status
while the override is in effect.
Extreme stall
duration
Service
(10 to 20 minutes; default 10) – This setpoint applies to both VGD controls. This
setpoint specifies the maximum allowed time an extreme stall condition can exist
before the VGD operation is disabled and driven to the full open (100%) position.
VGD 1: High limit Service
(0.5-1.2 VDC; default 0.8) – 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 0.1 VDC.
If a Low Limit setpoint is entered which is less than 0.1 VDC below the High Limit
setpoint, the High Limit setpoint is adjusted so that it is 0.1 VDC above the newly
entered Low Limit value.
VGD 1: Low limit Service
(0.4-0.8 VDC; 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 0.1 VDC below the High Limit
setpoint, the High Limit setpoint is adjusted so that it is 0.1 VDC above the newly
entered Low Limit value.
VGD 2: High limit Service
(0.5-1.2 VDC; default 0.8) – 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 0.1 VDC.
If a Low Limit setpoint is entered which is less than 0.1 VDC below the High Limit
setpoint, the High Limit setpoint is adjusted so that it is 0.1 VDC above the newly
entered Low Limit value.
VGD 2: Low limit Service
(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 0.1 VDC below the High Limit
setpoint, the High Limit setpoint is adjusted so that it is 0.1 VDC above the newly
entered Low Limit value.
Model YD Mod D with OptiView Control Center 50