Power Supply; 24 Vdc Power Supply; 24 Vdc Safety Extra Low Voltage - Siemens SCALANCE X320-3LD FE Operating Instructions Manual

Connecting

6.5 Power supply

6.5 Power supply
6.5.1

24 VDC power supply

6.5.1.1

24 VDC safety extra low voltage

24 V safety extra-low voltage (SELV)
Operation only with safety-extra low voltage
• The IE Switch X-300 is designed for operation with safety extra-low voltage (SELV).
• The power supply unit for the IE Switch X-300 power supply must meet NEC Class 2, as
• The power of all connected power supply units must total the equivalent of a power
• If the device is connected to a redundant power supply (two separate power supplies),
• The signaling contact can be subjected to a maximum load of
• Never operate the device with AC voltage or DC voltage higher than 32 V DC.
Overvoltage protection for the power supply cables
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 was the "surge immunity test" according to EN61000-4-5. This
test requires overvoltage protection for the power supply lines (doe not apply to the
X-300EEC). A suitable device is, for example, the Dehn Blitzductor BVT AVD 24 article no.
918 422 or a comparable protective element.
Manufacturer: DEHN+SÖHNE GmbH+Co.KG, Hans Dehn Str. 1, Postfach 1640, D - 92306
Neumarkt, Germany.
Note
Device variants
There are devices with one power supply unit or with two power supply units. Depending on
the variant, the data cable outlet can be on the front or at the rear of the device.
132
WARNING
This means that only safety extra-low voltages (SELV) complying with
IEC950/EN60950/ VDE0805 can be connected to the power supply terminals.
described by the National Electrical Code(r) (ANSI/NFPA 70).
source with limited power (LPS limited power source).
both power supplies must meet these requirements.
100 mA (safety extra-low voltage (SELV), 24 VDC).
CAUTION
Operating Instructions, 05/2016, A5E01113043-20
SCALANCE X-300