Siemens SCALANCE W774-1

Connection
5.2 Power supply
SCALANCE W774-1 /W734-1
Operating Instructions, 01/2017, C79000-G8976-C325-08
39
5.2
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 unit.
SCALANCE W774/W734 RJ-45
For the power supply, there are two options with the SCALANCE W774/W734:
● Direct feed in via the four-pin socket (position
①)
For the direct feed-in power supply use copper cables with the following properties:
– Round cable cross-section with 6 to 8 mm diameter.
– Two-wire cable with 0.5 to 1.5 mm2 cross-section per wire.
– Permitted tensile load at least 100 N. - UL
– Listing of the cables according to the national installation regulations. In areas where
NEC or CEC applies: Type PTLC or ITC
● Power over Ethernet via the RJ-45 Ethernet interface P2 (position
②). The other
Ethernet interface P1 is not capable of PoE.
The four-pin connecting socket has the following pin assignment:
Pin
Assignment
L1+
24 VDC
M1 Ground