Emerson Vilter PLC, Operation Manual

Page: 59 / 118

9 – 3
Section 9 • Step and PID Device Control Screens
Blower Package PLC Operation Manual •Vilter/Emerson • 35391BLP
Figure 9-3. Water Cooled Aftercooler Screen
WATER COOLED AFTERCOOLER SETPOINTS
• Open Valve Above: De fi nes the temperature the af-
tercooler water supply valve will open to minimum
position.
• Target Aftercooler Outlet Temperature: De fi nes the
desired temperature of gas at the outlet of the after-
cooler. The aftercooler water supply valve position
will adjust to maintain this temperature.
• Deadband: Range above and below setpoint where
the controller will not make adjustments to water
supply valve positon.
• PID Tuning: PID Calculations displayed to aid in tun-
ing the PID loop.
• Loop Update Time: De fi nes the PID controller loop
time. The PID calculation will update every cycle of
the loop update timer.
• Proportional Gain (Kp): De fi nes the Proportional
Constant of the PID calculation.
• Integral Gain (Ki): De fi nes the Integral Constant of
the PID calculation.
• Derivative Gain (Kd): De fi nes the Derivative Constant
of the PID Calculation.
• Minimum Valve Open: De fi nes the minimum water
supply valve position.
• Aftercooler Valve Force: Allows the user to manu-
ally force the aftercooler water supply valve to a set-
table position. Activating the Aftercooler Valve Force
pushbutton will command the aftercooler water sup-
ply valve to go to the set position, and will override
calculations from the PID Controller.