Connecting up
5.4 24 VDC power supply
SCALANCE XR-300WG
Operating Instructions, 05/2017, C79000-G8976-C454-01
41
24 VDC power supply
Safety extra low voltage
The device is designed for operation with a directly connectable safety extra-low voltage
(SELV).
Suitable fusing for the power supply cables
The current on the terminal may not exceed 5 A. Use a fuse that protects against currents >
5 A. The fuse must meet the following requirements:
• In areas where NEC or CEC applies:
– Suitable for DC (min. 60 V / max. 5 A)
– Breaking current at least 10 kA
– Approval according to ANSI/UL 248-1 or CSA C22.2 No. 248.1
– Classes R, J, L, T or CC
– Suitable for the protection of DC power supply circuits
• In other areas:
– Suitable for DC (min. 60 V / max. 5 A)
– Breaking current at least 10 kA
– Approval in compliance with IEC 60127-1 / EN 601127-1
– Switch off characteristics: B or C for circuit breakers and fuses
– Suitable for the protection of DC power supply circuits
You do not need to fuse the supply cable if you only use power sources with a limited
power source (LPS) or power sources according to NEC Class 2 for the power supply of
the devices.