Danfoss VLT FC 300 Design Guide

3.4.4 Example of Process PID Control
The following is an example of a Process PID Control used
in a ventilation system:
Temperature
Fan speed
Temperature
transmitter
Heat
Heat
generating
process
Cold air
130BA218.10
100kW
n °CW
In a ventilation system, the temperature is to be settable
from - 5 - 35°C with a potentiometer of 0-10V. 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.
Transmitter
96 97 9998
91 92 93 95
50
12
L1 L2
L1
PEL3
W PEVU
F1
L2
L3
N
PE
130BA175.11
18
53
37
55
54
M
3
Illustration 3.7 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).
Introduction to FC 300 FC 300 Design Guide
34 MG.33.BD.02 - VLT
®
is a registered Danfoss trademark
3
3

Danfoss VLT FC 300 Specifications

General

Brand	Danfoss
Model	VLT FC 300
Category	DC Drives
Language	English