Connection
6.2 Power supply
SCALANCE WxM766
Operating Instructions, 03/2022, C79000-G8976-C617-03
55
The digital outputs are not permitted to come into contact with hazardous voltages and
non-energy limited circuits. The permissible nonhazardous voltages are SELV/PELV as
per UL 61010-2-201. The energy limited circuit as per clause 9.4 of UL 61010-1 or LPS
of UL 60950 or Class 2 of UL 1310 or UL 5085-1 & UL 5085-3 are considered as
equivalent.
6.2 Power supply
Note
Galvanic isolation of the power supply unit
To ensure dielectric strength according to IEEE 802.3, the supplying 24 V power supply
unit must be galvanically isolated with a dielectric strength of 1500 VAC. The galvanic
isolation must also not be bridged by
other devices connected to the same power supply
Note
All power supplies (24 V power supply unit or PoE) must not be connected to a mains
supply higher than 300 V and the overvoltage category II.
Information on the power supply
There are two options for the power supply:
• Power over Ethernet via the 8-pin M12 Ethernet interface P1 ①
The power supply cannot be connected redundantly.
• Direct infeed via the 4-pin M12 socket ②
The power supply can be connected redundantly. The inputs L1/L2 are decoupled
There is no distribution of load. The power supply unit with the higher output voltage
supplies the device alone.
For the direct feed-in of the power supply use copper cables with the following
properties:
• Round cable cross-section with 6 to 8 mm diameter.
• Two-wire cable with a cross-section of 0.75 to 1.5 mm
2
per wire or copper cable of
the category AWG18-16. The temperature stability must be at least 105 °C.
• With redundant power supply: Four-wire cable with a cross-section of 0.75 to 1.5 mm
2
per wire or copper cable of the category AWG18-16. The temperature stability must
be at least 105 °C.