Power Over Ethernet - Siemens SCALANCE W788-1PRO Operating Instructions Manual

Safety extra-low voltage (SELV)
Warning
!
The SCALANCE W78x devices are designed for operation with safety extra-low
voltage (SELV). Therefore only safety extra-low voltage (SELV) with limited power
source (LPS) complying with IEC950/EN60950/VDE0805 may be connected to the
power supply terminals.
The power supply unit to supply the SCALANCE W78x must comply with NEC
Class 2 (voltage range 18 - 32 V, current requirement 1 A)
The device may only be supplied by a power supply unit that meets the
requirements of class 2 power sources of the "National Electrical Code, table 11
(b )". If the power supply is designed redundantly (two separate power supplies),
both m ust meet these requirements.
Exceptions:
• Power supply with PE
generated rated voltage does not exceed the voltage limits 25 V AC or 60 V DC.
• Power supply by a SELV power source (according to IEC 60950) or PELV
power source (according to VDE 0100-410) without limited power is also
permitted if suitable fire protection measures are taken by:
- Installation in a cabinet or suitable enclosure
- Installation is a suitably equipped, closed room
Grounding
Caution
There must be no potential difference between the following parts otherwise there
is a risk that the device will be destroyed:
• Ground potential of the power supply and ground potential of the antenna
ground.
• Ground potential of the power supply and a grounded housing.
• Ground potential of the power supply and the ground potential of the device
connected to Industrial Ethernet (for example PC, AS-300, AS-400 etc.)
Connect both grounds to the same foundation earth or use an equipotential
bonding cable.

Power over Ethernet

Connecting several SCALANCE W7xx devices with PoE supply from a common
PoE switch (acting as power supply) is not possible.
Operating Instructions SCALANCE W78x
C79000-G8976-C184-07
Description of the SCALANCE W78x
LV (according to VDE 0100-410) is also possible if the
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