York YST Operation Manual page 68

SECTION 2 - OPTIVIEW CONTROL CENTER INTRODUCTION
prograMMable/diSplaY onlY
governor (Min rated)
Screen: Capacity Controls
SP (SSP2) Range: 3200-3600 RPM
RR (RRSP4) Range: 100-200 RPM/Sec
PID Tuning Ranges - P: 0.00-5.00
PID Tuning Defaults - P: 0.75
This box displays parameters pertinent to the Gover-
nor (Speed Control) PID Logic during the ramp up to
rated speed to maintain the speed (PV) at the setpoint
(SP). The output (CV) displayed will decrease to close
the governor valve if the speed increases above the
setpoint. The setpoint is automatically ramped from
the SSP1- Slow Roll Speed to the SSP3 – Fixed Speed
shown on the Speed Setpoints Screen at the ramp rate
(RR) shown as long as the Speed Setpoint is in the Auto
mode. The green Auto text changes to yellow Manual
text to show the status of the Speed Setpoint as pres-
ently selected on the Auto/Manual Screen.
governor (rated)
Screen: Capacity Controls
SP Range: 3200-4700 RPM
RR (RRSP4) Range: 1-200 RPM/Sec
PID Tuning Ranges - P: 0.00-5.00
PID Tuning Defaults - P: 1.20
This box displays parameters pertinent to the Gover-
nor (Speed Control) PID Logic during normal opera-
tion at the minimum rated speed or above to maintain
the speed (PV) at the setpoint (SP). The output (CV)
displayed will decrease to close the governor valve if
the speed increases above the setpoint. The setpoint is
automatically ramped to the setpoint dictated by the
capacity/anti-surge controls after the turbine stabiliza-
tion period at the ramp rate (RR) shown as long as the
Speed Setpoint is in the Auto mode and will never be
allowed drop below SSP2-Minimum Rated Speed nor
rise above SSP9-Maximum Rated Speed shown on the
Speed Setpoints Screen. The green text shows the Auto
or Manual status of the Speed Setpoint as presently se-
lected on the Auto/Manual Screen.
68
SP (SSP2) Default: 3200 RPM
RR (RRSP4) Default: 200 RPM/Sec
I: 0.00-5.00 D: 0.00-5.00
I: 2.00 D: 0.00
SP Default: 4500 RPM
RR (RRSP4) Default: 10 RPM/Sec
I: 0.00-5.00 D: 0.00-5.00
I: 1.21 D: 0.00
gov valve position limit
Screen: Capacity Controls
SP (GSP1) Range: 20.0-100.0 %
PID Tuning Ranges - P: 0.00-5.00
PID Tuning Defaults - P: 1.00
This box displays parameters pertinent to the Governor
Valve Position Limit power limiting override control-
ler which is active only when MSSP8-Power Limiting
Mode on Capacity Control Setpoints Screen 1 is set for
Position. The output (CV) displayed will decrease to
reduce the speed setpoint, close the vanes, and open the
hot gas valve if required to maintain the governor valve
output signal (PV) at the setpoint (SP). The setpoint is
usually determined by observing the Governor Valve
output signal at normal full load conditions and then
entering this percent as the setpoint of this control-
ler. The green Inactive text changes to yellow Active
to display if the controller is presently controlling the
chiller capacity.
horsepower limit
Screen: Capacity Controls
SP (HLSP) Range: Variable
PID Tuning Ranges - P: 0.00-5.00
PID Tuning Defaults - P: 1.00
This box displays parameters pertinent to the Horse-
power Limit override controller which is active only
when MSSP8-Power Limiting Mode on Capacity Con-
trol Setpoints Screen 1 is set for Horepower. The out-
put (CV) displayed will decrease to reduce the speed
setpoint, close the vanes, and open the hot gas valve
if required to maintain the turbine horsepower (PV) at
the setpoint (SP). The horsepower setpoint is initially
set to the maximum allowable based on the compres-
sor model entered on the Setup Screen. It is factory
adjusted to the lower of the compressor maximum or
115% of the turbine design horsepower and can only
be changed in the TEST OP or ADMIN ACCESS level.
The turbine horsepower (PV) is automatically calcu-
lated by the program based on the inlet, first stage, and
exhaust steam conditions. The green text changes to
Inactive or Active to display if the controller is pres-
ently controlling the chiller capacity.
FORM 160.67-O1
ISSUE DATE: 4/1/2015
SP (GSP1) Default: 100.0 %
I: 0.00-5.00 D: 0.00-5.00
I: 1.50 D: 0.00
SP Default: 840
I: 0.00-5.00 D: 0.00-5.00
I: 1.50 D: 0.00
JOHNSON CONTROLS