Connecting
5.2 24 VDC power supply
SCALANCE XR-500
48
Operating Instructions, 05/2014, A5E03275845-05
5.2
24 VDC power supply
Notes on the power supply
CAUTION
Overvoltage protection for the power supply cables
If SCALANCE XR-500s 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 the SCALANCE XR-500 to electromagnetic
interference is the "surge immunity test" according to EN 61000-4-5. This test requires
overvoltage protection for the power supply lines. The following type is, for example,
suitable:
Dehn Blitzductor BVT AVD 24, order number 918 422
Manufacturer: DEHN + SÖHNE GmbH + Co. KG, Hans Dehn Str. 1, Postfach 1640, D-
92306 Neumarkt, Germany.
Information on the power supply
●
The power supply is connected using a 4-pin plug-in terminal block. The terminal block
ships with the device.
●
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 SCALANCE XR-500 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.
●
To wire up the power supply connector, use copper cable of the category 14 AWG - 10
AWG or cable with a cross-sectional area of 1.5 mm
2
to 4 mm
2
.
WARNING
Operation only with safety extra-low voltage
•
The device is designed for operation with a directly connectable safety extra-low voltage
(SELV). (This does not apply to 100 to 240 V devices). This means that only safety
extra-low voltages (SELV) complying with IEC 60950-1 / UL 60950-1 / EN 60950-1 /
VDE 0805-1 may be connected.
•
Do not operate the device with AC voltage or DC voltage higher than 32 VDC.
