Siemens RXB Series Basic Documentation page 81

Engineering of
lightning protection
equipment
Note
Lightning arresters for
primary protection
230/400 V mains network
KNX network
Routing cables
between buildings
For internal use only
Siemens
Building Technologies
VDI 6004, Sheet 2, Edition July 2007, "Protection of building services - Lightning
protection systems and surge protection" applies.
If lightning protection is required in a building, the active cores (see figure on
previous page) must be connected with lightning arresters. This is also
recommended in the following cases, for example, if:
The building is connected to a low voltage overhead cable.
The construction of the building includes metal parts which can be struck by
lightning, e.g. metal chimneys or aerials
There is another building with a lightning protection system in the vicinity.
During engineering, selection of the lightning arrester must be coordinated with
overvoltage protection equipment (note the information supplied by the
manufacturers on the use of their products).
Lightning arresters can discharge high-energy lightning current repeatedly without
damage. They are installed in the AC 230/400 V mains network and KNX network.
Lightning arrester (Class B) for the AC 230/400 V mains network:
Nominal leakage current of at least 10 kA (10/350 µs)
Protection level < 4 kV
Lightning arrester for the KNX network
Nominal leakage current of at least 1 kA (10/350 µs)
Protection level < 4 kV
Variant 1 with lightning arresters
When routing cables between buildings, lightning arresters must be installed where
the bus cable enters the building. They must be connected to the nearest
equipotential bonding point.
Surge arrester
(secondary protection)
Lightning arrester
(primary protection)
Bus
device
(room unit)
Equipotential bonding rail
KNX bus communications
Appendix
External
lightning protection
Bus
PE
device
(controller)
230/400 V
81 / 88
CE1P3127en
2013-04-08