3.4.4 Example of Process PID Control
The following is an example of process PID control used in a ventilation system:
In a ventilation system, the temperature is to be able to be set from 23°–
95°F (-5°–35°C) with a potentiometer of 0–10 Volt. The set temperature
must be kept constant, for which purpose the process control is to be
used.
The control is of the inverse type, which means that when the tempera-
ture increases, the ventilation speed is increased as well, so as to gen-
erate more air. When the temperature drops, the speed is reduced. The
transmitter used is a temperature sensor with a working range of 14°–
104°F (-10°–+40°C), 4–20 mA. / Max. speed 300 /1,500 RPM.
NOTE!
The example shows a two-wire transmitter.
1.
Start/Stop via switch connected to terminal 18.
2.
Temperature reference via potentiometer (23°–95°F (-5°–+35°C), 0–10 VDC) connected to terminal 53.
3.
Temperature feedback via transmitter (14°–104°F [-10°–+40°C], 4–20 mA) connected to terminal 54. Switch S202 set to ON (current input).
3 Introduction to AutomationDrive FC 300
FC 300 Design Guide
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