Periphery Wiring (Without Bus); Engineering Notes; Power Lines Ac 230 V; Transformer Design Ac 24 V - Siemens Desigo RXB Technical Manual

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Periphery wiring (without bus)

As a rule, comply with local regulations for electrical installations.
These take precedence over any notes in this document.
3.1

Engineering notes

The following topics require special attention.
3.1.1

Power lines AC 230 V

The sizing and fusing of the power lines are oriented to overall load and local
regulations.
The power lines must be fused on the controller with strain relief.
3.1.2

Transformer design AC 24 V

The DESIGO RXB controller is powered by AC 230 V; the RXL controller by AC 24
V.
Controllers with AC 230 V power internally generates the AC 24 V power supply for
connected field devices.
RXL controllers and amplifiers for thermal valve actuators UA1T, powered by AC 24
V, require a transformer.
The transformer for the power must meet requirements for protective extra-low
voltage (PELV) per EN 60742 or EN 61558-2-6.
Transformer sizing is oriented on the sum total of rated power of all connected
devices (See data sheet CA2N3591 for UA1T).
The transformer must be fused on the secondary side.
3.1.3 Wiring for Triac outputs AC 24 V and power supply
AC 24 V
The following applies for wiring to actuating devices such as valves, damper
actuators or protection connected to the Triac outputs on the controller:
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 can not be led in the same cable as the power lines.
–
See table below for maximum simple wiring lengths.
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Installation guide RXB, RXL
Periphery wiring (without bus)
CM110381en_01
28 Feb 2009