York YST - Figure 24 - PID Setup Screen 2; PID Setup Screen 2

JOHNSON CONTROLS
67
SECTION 2 - OPTIVIEW CONTROL CENTER INTRODUCTION
FORM 160.67-O1
ISSUE DATE: 4/1/2015
2
PID SETUP SCREEN 2
LD09268
FIGURE 24 - PID SETUP SCREEN 2
NOTE: OptiView™ Control Center Screens shown may NOT represent the exact screens according to the software version utilized.
OVERVIEW
This screen displays the present tuning parameters
used by the Governor (Speed Control) Logic. Because
of variations in chiller load, inlet steam and exhaust
steam pressures during various stages of startup and
operation, three different sets of tuning parameters
(Slow Roll/Min Rated/Rated) may be required in
order to provide stable speed control. The tuning
parameters are automatically loaded into the Governor
(Speed Control) PID Logic at the transition to the next
speed control range to provide the proper control.
Also shown are the tuning parameters used by the
Gov Valve Position Limit and Horsepower Limit PID
logic. Each of the controller boxes displays the input
process variable (PV) that is being controlled as well
as the controller output signal (CV) that repositions the
controlled device to maintain the process variable at
setpoint (SP). The response time of each controller is
determined by the Proportional (P), Integral (I), and
Derivative (D) tuning setpoints entered. In some cases,
a setpoint ramp rate (RR) is also available. All setpoints
require a login access level of Service or higher.
Service Technicians refer to YORK Service Manual
160.67-M3 for operation and a detailed explanation of
the tuning parameters.
Governor (Slow Roll)
Screen: Capacity Controls
SP (SSP1) Range: 750-1200 RPM SP (SSP1) Default: 1000 RPM
RR (RRSP3) Range: 25-100 RPM/Sec RR (RRSP3) Default: 50 RPM/Sec
PID Tuning Ranges - P: 0.00-5.00 I: 0.00-5.00 D: 0.00-5.00
PID Tuning Defaults - P: 1.68 I: 1.46 D: 0.00
This box displays parameters pertinent to the Governor
(Speed Control) PID Logic during the slow roll warm-
up of the turbine 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
0 to the SSP1- Slow Roll 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 presently selected on
the Auto/Manual Screen.