Connecting Devices With 24 V Dc Power Supply; Pelv - Siemens SIMATIC NET SCALANCE XR-300M EEC Series Compact Operating Instructions

The IE switches X300 EEC / XR300M EEC provide the following options for redundancy of the
100 to 240 VAC / 60 to 250 VDC power supply:
● Redundant terminal blocks
You can order the switch with redundant terminal blocks for the power supply. Each terminal
block has only 1 pin for 1 power supply.
● Redundancy of the power infeed is not possible with this version.
6.7.1

Connecting devices with 24 V DC power supply

The equipment is designed for operation with Safety Extra-Low Voltage (SELV) by a Limited
Power Source (LPS).
This means that only SELV / LPS complying with IEC 60950-1 / EN 60950-1 / VDE 0805-1
must be connected to the power supply terminals, or the power supply unit for the equipment
power supply must comply with NEC Class 2, as described by the National Electrical Code (r)
(ANSI / NFPA 70).
If the equipment is connected to a redundant power supply (two separate power supplies),
both must meet these requirements.
Note
A power source that supplies safety extra low voltage combined with a following NEC Class 2
power limiter also meets the requirements according to IEC 60950‑1 / EN 60950‑1 / VDE
0805‑1 or NEC Class 2. A suitable power limiter is for example the redundancy module SITOP
PSE202U NEC Class 2 (article number 6EP1962-2BA00).
6.7.1.1

PELV

Note
Safety extra-low voltage
The supply of the devices by PELV (Protective Extra Low Voltage) according to DIN VDE
0100-410 or IEC 60364-4-41 is permitted when the generated nominal voltage does not exceed
the voltage limits 25 VAC or 60 VDC.
SCALANCE XR-300M EEC
Compact Operating Instructions, 11/2019, A5E02661176-14
WARNING
Connecting
6.7 Power supply
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