Siemens SCALANCE XR-300M Operating Instructions Manual page 46

Connecting
5.6 Power supply
Damage to the device due to overvoltage
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 AVD 24 article no. 918 422 or a comparable protective
element.
Manufacturer: DEHN+SÖHNE GmbH+Co.KG, Postfach 1640, D-92306 Neumarkt,
Germany
Connecting to the supply voltage (SELV)
● The power supply is connected using a 4-pin plug-in terminal block.
● 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.
Terminal block assignment (4-pin)
Table 5- 2 Pinout of the 24 V safety extra-low voltage (SELV)
Pin number
Pin 1
Pin 2
Pin 3
Pin 4
To wire up the power connector, use a copper cable of category 18-12 AWG or cable with a
cross-section of 0.75 to 2.5 mm².
46
CAUTION
Assignment (24 VDC)
L1+ (24 VDC)
M1
M2
L2+ (24 VDC)
Labeling (example)
Compact Operating Instructions, 05/2016, A5E02661171-11
SCALANCE XR-300M