Siemens S7-400 Installation Manual page 274

Assembling and Installing Systems
Diagram of the Lightning Protection Zones
The following diagram illustrates a lightning protection zone concept for a detached
building.
External
Lightning
Protection
Energy-
Technical
Cable
Information-Technical Cable
Figure A-6
Principle of Transitions between the Lightning Protection Zones
At the transition points between the lightning protection zones, you must take
measures to prevent surges being conducted further.
The lightning protection zone concept also states that all lines at the transitions
between the lightning protection zones that can carry lightning stroke current must
be included in the lightning protection equipotential bonding.
Lines that can carry lightning stroke current include:
• Metal pipelines (for example, water, gas and heat)
• Power cables (for example, line voltage, 24 V supply)
• Data cables (for example, bus cable).
A-22
Lightning Protection Zone 0, Field Side
Lightning Protection Zone 1
Lightning Protection
Zone 2
Lightning
Protection
Zone 3
Device
Metal
Component
Lightning Protection Zones of a Building
S7-400 and M7-400 Programmable Controllers Hardware and Installation
Building
Shield
(Steel
Reinforcement)
Room Shield
(Steel
Reinforcement)
Device Shield
(Metal Housing)
Non-
Electrical
Cable
(Metal)
Internal
Cable
Lightning Protection
Equipotential Bonding
Local
Equipotential Bonding
Galvanic
Connection
A5E00069481-04