Emerson Vilter PLC, Operation Manual

Page: 57 / 118

9 – 1
Section 9 • Step and PID Device Control Screens
Blower Package PLC Operation Manual •Vilter/Emerson • 35391BLP
Figure 9-1. Aftercooler (VFD Type) Screen
AFTERCOOLER (VFD TYPE) SETPOINTS
• Start Aftercooler Above: De fi nes the temperature the
aftercooler fans will come on at minimum speed.
• Target Aftercooler Outlet Temperature: De fi nes the
desired temperature of gas at the outlet of the after-
cooler. The aftercooler fan speed will adjust to main-
tain this temperature.
• Deadband: Range above and below setpoint where
the controller will not make adjustments to fan speed.
• 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 Speed: De fi nes the minimum aftercooler
fan speed.
• Aftercooler VFD Force: Allows the user to manu-
ally force the aftercooler fan(s) to a settable speed.
Activating the Aftercooler VFD Force pushbutton
will command the aftercooler fan(s) to go to the set
speed, and will override calculations from the PID
Controller.
Aftercooler Screens