Wiring For Triac Outputs Ac 24 V - Siemens Desigo TRA Engineering, Mounting And Installation Manual

Cable material
Cable laying
Cable length and cross section
DXR2... room automation
stations
PXC3 with TX-I/O triac
modules:
Caution!
Cable length
Notes
Siemens
Building Technologies
7.2

Wiring for Triac outputs AC 24 V

The following applies for wiring to actuating devices such as valves, damper
actuators or protection connected to the Triac outputs:
Use stranded, 2 or multiple core round cables, screened (standard off-the-shelf
installation cable).
Single wires may not be used.
Wiring may be laid together with power lines (AC 230 V).
They must be isolated from the power lines per regulations. Isolation must meet
PELV requirements.
Wiring cannot be led in the same cable as the power lines.
Triacs are protected against overload.
Cable cross section >= AWG20 / 0.75 mm
Cable length <= 80 m / 260 ft (EM interference).
Use cable cross section suited for 10 A according to local regulations
(T 10 A fuse in the power supply module / room automation station).
Cable length <= 300 m / 1000 ft (EM interference).
Calculation is based on a voltage drop of 0.48 V = 2% of 24 V (the triac and the
PTC protection resistor have a voltage drop of 6%).
Cable cross section
Power
2
/ AWG14
2.50 mm
2
/ AWG16
1.50 mm
2 / AWG18
1.00 mm
2
/ AWG20
0.75 mm
The outgoing and return cables may each have the indicated length.
Power = permanent load. The higher starting current of thermal or motorized
actuators is admissible.
Desigo TRA Engineering, mounting and installation
Wiring of field devices (without bus)
2
.
Cable length
1 VA 2 VA
300 m 300 m 140 m
1000 ft 1000 ft 440 ft
300 m 210 m
1000 ft 700 ft 280 ft
270 m 135 m
880 ft 440 ft 180 ft
170 m 85 m
550 ft 275 ft 110 ft
5 VA 10 VA 20 VA
70 m
220 ft 110 ft
85 m 42 m
140 ft
50 m 25 m
90 ft
33 m 16 m
55 ft
CM111043en_09
2016-02-22
35 m
21 m
70 ft
13 m
45 ft
8 m
27 ft
39 / 84