Connecting
5.6 Connecting the external 24 VDC power supply
SCALANCE X-300M PoE
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Compact Operating Instructions, 05/2016, A5E02630810-09
5.6
Connecting the external 24 VDC power supply
Safety extra-low voltage and measures for protecting against overvoltage
WARNING
The equipment is designed for operation with Safety Extra-Low Voltage (SELV) by a
Limited Power Source (LPS).
This means that only SELV / LPS (Limited Power Source) complying with IEC 60950-1 / EN
60950-1 / VDE 0805-1 must be connected to the power supply terminals. 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.
CAUTION
If IE Switches X-300 are supplied over long 24 V power supply lines or networks, measures
are necessary to prevent interference by strong electromagnetic pulses on the supply lines.
These can result, for example, due to lightning or switching of large inductive loads.
One of the tests used to attest the immunity of devices of the IE Switches X-300 to
electromagnetic interference is the "surge immunity test" according to EN61000-4-5. This
test requires overvoltage protection for the power supply lines. A suitable device is, for
example, the Dehn Blitzductor BVT ALD 36, order number 918 408 or comparable
protective element.
Vendor: DEHN+SÖHNE GmbH+Co.KG, Postfach 1640, D-92306 Neumarkt, Germany
Connecting to the supply voltage (SELV)
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The power supply is connected using a 4-pin plug-in terminal block.
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The power supply can be connected redundantly. Both inputs are isolated. There is no
distribution of load. When a redundant power supply is used, the power supply unit with
the higher output voltage supplies the IE Switch X-300 alone.
●
The power supply is connected over a high resistance with the enclosure to allow an
ungrounded set up. The two power inputs are non-floating.
