Siemens SIMATIC NET SCALANCE W760 Operating Instructions Manual page 16

Connection
5.1 Lightning protection, power supply and grounding
Note
We recommend that you use the maintenance-free lightning protector LP798-2N.
Exception: When there is also DC power supplied via the antenna cable. In this case, only
the lightning protector LP798-1N can be used.
Danger due to lightning strikes
Installing this lightning protector between an antenna and a SCALANCE W700 is not
adequate protection against a lightning strike. The LP798-1N lightening protector only
works within the framework of a comprehensive lightning protection concept. If you have
questions, ask a qualified specialist company.
Note
The requirements of EN61000-4-5, surge immunity tests on power supply lines, are met only
when a Blitzductor is used with 24 VDC:
BVT AVD 24
type no. 918 422
Manufacturer: DEHN+SÖHNE GmbH+Co.KG, Hans Dehn Str. 1, Postfach 1640, D -
92306 Neumarkt, Germany
Supply voltage
Safety extra low voltage
The equipment is designed for operation with Safety Extra-Low Voltage (SELV) by a
Limited Power Source (LPS).
This means that only SELV / LPS (Limited Power Source) complying with IEC 60950-1 / EN
60950-1 / VDE 0805-1 must be connected to the power supply terminals or the power
supply unit for the equipment power supply must comply with NEC Class 2, as described by
the National Electrical Code (r) (ANSI / NFPA 70).
If the equipment is connected to a redundant power supply (two separate power supplies),
both must meet these requirements.
Transient overvoltages
Take measures to prevent transient voltage surges of more than 40% of the rated voltage.
This is the case if you only operate devices with SELV (safety extra-low voltage).
16
WARNING
WARNING
WARNING
Operating Instructions, 03/2015, C79000-G8976-C322-05
SCALANCE W760/W720