Example Of Process Pid Control - Danfoss VLT AutomationDrive FC 360 Design Manual

Product Overview

2.5.4 Example of Process PID Control

2 2
Illustration 2.26 is an example of a process PID control used
in a ventilation system:
Cold air
W
Illustration 2.26 Process PID Control in a Ventilation System
In a ventilation system, the temperature can be set from -5
to 35 °C with a potentiometer of 0–10 V. Use the process
control to keep the set temperature constant.
The control is inverse, which means that when the
temperature increases, the ventilation speed is increased as
well, 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 to 40 °C,
4–20 mA. minimum/maximum speed 300/1500 RPM.
34
100kW
Heat
generating
process
n °C
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Design Guide
L1
L2
L3
N
PE
F1
91 92 93 95
L1 L2
Temperature
transmitter
U
96 97
Illustration 2.27 2-wire Transmitter
1.
2.
3.
12
27
L3 PE
18
50
53
55
V W PE
54
98 99
M
3
Start/Stop via the switch connected to terminal
18.
Temperature reference via potentiometer (-5 to
35 °C, 0–10 V DC) connected to terminal 53.
Temperature feedback via transmitter (-10 to 40
°C, 4–20 mA) connected to terminal 54.
Transmitter
MG06B402