Siemens SIMATIC ET 200AL, System Manual

Page: 2249 / 2255

Lightning protection and overvoltage protection
7.3 Rules and components for the transitions between lightning protection zones
Designing interference-free controllers
Function Manual, 06/2014, A5E03461486-AB
31
Seq.
no.
Cables for ... Connection at the 0
A
interface to 1 with:
S7-1500/ET 200MP/ET 200SP/ET 200AL Article
number
11 Inputs/outputs of
analog modules
(e.g., 4-20 mA,
1-10 V)
BLITZDUCTOR® XT, base section BXT BAS 920 300
BLITZDUCTOR® XT, module
(I
L
= 1.2 A) (4-wire)
920 310
* Version with remote indication contact
Components of the series BLITZDUCTOR® XT can be remotely monitored with the appropriate
accessories. Additional information is available on the Internet ( http://www.dehn.de )
Components can be ordered directly from:
DEHN+SÖHNE GMBH+CO.KG.
Hans-Dehn-Straße 1
D-92318 Neumarkt
Rule for the transition from lightning protection zone 0
B
to 1, 1 to 2, or 2 to 3
The transition from lightning protection zone 0
B
to 1, 1 to 2, or 2 to 3 prevents strong
electromagnetic coupling and serves as overvoltage protection. The following applies to the
transition at the interface from lightning protection zone 0
B
to 1, 1 to 2, or 2 to 3:
● Use of power cables with surge current-carrying cable shields or twisted-pair IT cables
● Laying cables and lines
–
In continuous, surge current-carrying metal pipes that are grounded at both ends
– In reinforced concrete channels capable of carrying surge current with grounding at
both ends
– On closed metal cable racks that are grounded at the beginning and end
● Use of fiber-optic cables without a metal shield if such a transmission is intended
● Creation of local equipotential bonding at the transition of lightning protection zones, with
incorporation of metallic supply systems (for example, pipes, air ducts, cable channels or
cable ducts)
Additional measures
If the actions listed above cannot be implemented, protection by means of overvoltage
arresters must be provided. The following sections contain tables with overvoltage arresters
that are very suitable for protecting the plant.