Danfoss vlt fcd 302, Руководство по конструкции

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Step 4: Use Table 4.23 to calculate the necessary PID
control parameters.
4.4.9 Example of Process PID Control
Illustration 4.10 is an example of a Process PID Control
used in a ventilation system.
130BC966.10
5
6
1
100kW
n °C W
2
3
4
ON WARNING ALARM
Bus MS NS2 NS1
Illustration 4.13 Process PID Control in Ventilation System
Item Description
1 Cold air
2 Heat generating process
3 Temperature transmitter
4 Temperature
5 Fan speed
6 Heat
Table 4.24 Legend
In a ventilation system, the temperature is to be settable
from -5 to 35 °C with a potentiometer of 0 to 10 V. The
task of the process control is to maintain temperature at a
constant preset level.
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
to 40
°
C, 4-20 mA. Min./Max. speed 300/1500 RPM.
Transmitter
96 97 99 98
91 92 93 95
50
12
L1 L2
L1
PE L3
W PE V U
F1
L2
L3
N
PE
130BA175.12
18
53
37
55
54
M
3
5 kΩ
Illustration 4.14 Two-wire Transmitter
1. Start/Stop via switch connected to terminal 18.
2. Temperature reference via potentiometer (-5 to
35
°
C, 0 to 10 V DC) connected to terminal 53.
3. Temperature feedback via transmitter (-10 to 40
°
C, 4 to 20 mA) connected to terminal 54. Switch
S202 set to ON (current input).
Application Examples
VLT
®
Decentral Drive FCD 302
MG04H102 - VLT
®
is a registered Danfoss trademark 61
4 4