GE AF-650 GP Design Manual page 33

3.4.4 Example of Process PID Control
The following is an example of a Process PID Control used in a ventilation system:
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In a ventilation system, the temperature is to be settable from - 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 temperature
increases, the ventilation speed is increased as well, so as to generate more
air. When the temperature drops, the speed is reduced. The transmitter used
is a temperature sensor with a working range of -10-40°C, 4-20 mA. Min. /
Max. speed 300 / 1500 RPM.
NB!
The example shows a two-wire transmitter.
1. Start/Stop via switch connected to terminal 18.
2. Temperature reference via potentiometer (-5-35°C, 0-10 VDC) connected to terminal 53.
3. Temperature feedback via transmitter (-10-40°C, 4-20 mA) connected to terminal 54. Switch S202 set to ON (current input).
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AF-650 GP Design Guide