Page 7 - DS225 Modern-buildings

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Earthing Functional from scratch

Earthing and pad foundations

Whether existing or new buildings, a functioning earth-termination system is the
pre-requisite for the safe operation of electric systems in buildings and for protecting
people from dangerous high voltages.
C

The design and implementation of the earth-termination system are of central importance. After the concrete has set, it is no
longer possible to retrofit this vital component, e.g. in the form of a foundation earth electrode. Omissions or errors during the
construction phase cannot be corrected later or, at least, not without a great deal of effort and expense.

Foundation and ring earth electrodes

Foundation or ring earth electrodes are a safe and cost-effective earth-termination
system – over the entire lifetime of the building.
B The foundation earth electrode is installed in the concrete foundation and covered by
at least 5 cm of concrete to ensure corrosion protection. However, in some cases this
conductive earth connection may no longer be ensured (foundations with increased
B earth contact resistance) due to various building construction measures (e.g. when
A constructing a building made of waterproof concrete). A corrosion-resistant ring
A earth electrode must then be installed in the ground outside the building foundation
and connected to a ring equipotential conductor in the foundation.

Components of the earth-termination system

A Foundation and ring earth electrode Product examples Part No.
High-quality earthing materials from Foundation earth electrode
DEHN provide a solid foundation Strip steel, hot-dip galvanised 852 335
for the building’s earth-termination Round steel, hot-dip galvanised 800 010
system. Depending on the type of Rebar clamp
building, a foundation earth electrode DEHNclip
is installed in the foundation and, - Rd 8-9 / Rd 10 308 131
if required, an additional ring earth - Rd 8-9 / Fl 30 x 3-4 308 141
electrode outside the foundations. Ring earth electrode Foundation earth electrode Ring earth electrode
Round steel, StSt V4A 860 010 Conventional foundation in direct contact with Foundation with increased earth contact resistance
Cross clamp 319 209 earth according to DIN 18014 Ring earth electrode with functional bonding
conductor according to DIN 18014
B Main earthing busbar and fixed earthing terminal Product examples Part No.
If a ring earth electrode is installed, it Wall bushing 478 540
must be connected to the functional Equipotential bonding bar 563 200
bonding conductor in the foundation, Pad foundation
thus ensuring a professional earth-
termination system.
Buildings with pad foundations (e.g. for columns) must be connected to a founda-
tion earth electrode with a length of at least 2.5 m in each foundation. To establish
C Connections to the lightning protection system Product examples Part No. equipotential between the pad foundations, these pad foundations must be inter-
It is advisable to provide connections Earth entry V4A 860 130 connected in such a way that they are electrically conductive and corrosion-resistant.
for an external lightning protection Rod holder V4A 274 160
system when constructing a new Anti-corrosion tape 556 125
building. If terminal lugs are installed MV clamp V4A 390 079
alreday, an external protection system
can be installed already, retrofitted
more easily at lower cost.

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