York YST Operation Manual page 72

SECTION 2 - OPTIVIEW CONTROL CENTER INTRODUCTION
prograMMable
anti-Surge Setpoints - high head press delta
(pd1)
Range: 20-120 PSID
This is the maximum head that the chiller will likely
see in normal operation. The Anti-Surge Conditions
data fields will show the calculated High Head Min
Speed (MS%) and PRV (MV%) values when the pres-
ent Head Pressure (PD) is at this value.
anti-Surge Setpoints - high head Min prv
(Mvp1)
Screen: Capacity Controls
Range: 5-50 %
This is the minimum PRV control signal allowed when
the head is equal to the High Head Pressure Delta
setpoint PD1.
anti-Surge Setpoints - high head Min Speed
(MSp1)
Screen: Capacity Controls
Range: 3200-4700 RPM
This is the minimum speed allowed when the head is
equal to the High Head Pressure Delta setpoint PD1. It
is only utilized when MSSP7-Speed Control Mode is
set for Variable.
anti-Surge Setpoints - low head press delta
(pd2)
Screen: Capacity Controls
Range: 30-80 PSID
This is the minimum head that the chiller will likely
see in normal operation while running at or above the
minimum rated speed. The Anti-Surge Conditions data
fields will show the calculated Low Head Min Speed
(MS%) and PRV (MV%) values when the present
Head Pressure (PD) is at this value.
anti-Surge Setpoints - low head Min prv
(Mvp2)
Range: 0-50 %
This is the minimum PRV control signal allowed when
the head is equal to the Low Head Pressure Delta
setpoint (PD2).
72
Screen: Capacity Controls
Default: 75 PSID
Default: 20 %
Default: 4500 RPM
Default: 40 PSID
Screen: Capacity Controls
Default: 15 %
anti-Surge Setpoints - low head Min Speed
(MSp2)
Range: 3200-4500 RPM
This is the minimum speed allowed when the head is
equal to the Low Head Pressure Delta setpoint (PD2).
Even if the Low Head Min Speed is set
lower than the SSP2-Minimum Rated
Speed Setpoint on the Speed Setpoints
Screen, the speed setpoint will never be
allowed to go below the minimum rated
speed.
Set anti-Surge Setpoints Key
Access Level Required: SERVICE
This key enables the field selection cursor in the Anti-
Surge Setpoints box. The operator may then toggle be-
tween the programmable data fields using the Cursor
Arrow keys.
output Control Key (Speed/vanes/hot gas/
Subcool/hotwell/Stm inlet/Stm bypass)
Access Level Required: SERVICE
This key is used to select the output signal to be manu-
ally controlled. The Stm Inlet/Stm Bypass selections
only appear if MSSP4-Turbine Start Mode is set for
Auto on Configuration Screen 1.
Switch to Manual Key
Access Level Required: SERVICE
This key places the selected output signal in Manual
and displays the Increase/Decrease/Set keys that are re-
quired to manipulate the manual control signal. It will
not function while the messages START SEQUENCE
INITIATED or SYSTEM COASTDOWN are dis-
played. When pressed, the key text changes to Green
text Switch to Auto. If the control signal is manually
changed more than 5% from the Auto signal, the text
changes to Red.
increase Key
Access Level Required: SERVICE
This key increases the Manual control signal 1% each
time it is pressed.
FORM 160.67-O1
ISSUE DATE: 4/1/2015
Screen: Capacity Controls
Default: 3600 RPM
JOHNSON CONTROLS