Equipotential bonding

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Main earthing rail for protective equipotential bonding
Symbol for equipotential bonding according to IEC 60417-5021 (2002-10)

Equipotential bonding refers to a connection with good electrical conductivity that minimizes different electrical potentials . Equipotential bonding is often referred to colloquially as earthing . The requirement for equipotential bonding results from the "Requirements for protection against electric shock" and is specified internationally in IEC 60364-4-41: 2005 and for Germany in DIN VDE 0100-410: 2007-06. The connection of all conductive bodies (housings) of electrical equipment with an earthed protective conductor and with the main earthing rail is the basis for protection against electric shock. The protective measure of "automatic shutdown of the power supply in the event of a fault", which is given priority in the VDE, is ensured by a standard-compliant execution with subsequent testing of the system. The test also proves that the loop impedance is sufficiently small for automatic shutdown in the event of a fault.

The technical design for equipotential bonding, the dimensioning of the cross-sections and the standardized terms result from IEC 60364-5-54: 2011 and for Germany from DIN VDE 0100-540: 2012-06.

The main equipotential bonding is established in the house connection room of a building. Earthing conductors , all protective equipotential bonding conductors and the protective conductors of the power supply, which are all brought together on a main earthing rail , must be integrated. About the grounding conductor to connect to the will foundation earth or another type of earth electrode made. If necessary, there are connections from the foundation earth to the down conductors of a lightning protection system (LPS).

Definition according to VDE

According to DIN VDE 0100 Part 200, equipotential bonding is defined as follows: "Establishing electrical connections between conductive parts in order to achieve equipotential bonding."

Protective equipotential bonding

The protective equipotential bonding is the equipotential bonding between all external conductive parts leading into a building (such as metal water pipes, sewer pipes or gas pipes (with insulating spacer)) as well as "external conductive parts in the building" such as metal cables, air conditioning, heating and "conductive parts in the reach of people “And the main earthing rail ( main equipotential bonding rail ).

All these parts are to be connected to the main earthing rail using protective equipotential bonding conductors.
As a rule, the connections are made with copper cables with a minimum cross-section of 2.5 mm 2 for mechanically protected or 4 mm 2 for unprotected installation.

In order to prevent potential differences from being carried over from the ground, buildings have only been earthed at a single point since 2010. If a conductive pipe is introduced into the building from the outside, an insulated pipe connection should be provided at the house connection .

Local equipotential bonding

By connecting all protective conductors in a terminal rail, a local equipotential bonding is established in the sub-distribution (installation distributor). As a rule, all neutral conductors are connected to one another via another clamping rail .

A local potential equalization is a potential compensation between all electrically conductive parts in a room or area and the protective conductor of the guided into the room or area lines for low voltage .

According to DIN VDE 0100 Group 700, it is prescribed in rooms and areas with particular danger:

  • Rooms with bathtub or shower (part 701)
  • Pools of swimming pools and other pools (part 702), sauna
  • Agricultural and horticultural properties (part 705)
  • Medically used rooms (part 710)
  • Damp rooms (this does not mean domestic showers and baths in this context)
  • Fire hazard areas
  • Potentially explosive areas
  • Industrial building

This equipotential bonding is also generally implemented with copper cables with a minimum cross-section of 2.5 mm 2 for mechanically protected or 4 mm 2 for unprotected installation.

Within a building, a local protective equipotential bonding is connected to the main equipotential bonding rail via a protective equipotential bonding conductor.

See also:

Rooms with a bathtub or shower

After the last revision, DIN VDE 0100-701 edition 2008-10 only requires the local equipotential bonding of the pipes and systems of the water, sewage, heating, air conditioning and gas installations by connecting them to each other and to the protective conductor rail in the distribution board or directly be connected to the main equipotential bonding rail.

The inclusion of conductive bathtubs and shower trays is no longer necessary, but possible. An existing equipotential bonding of metal bathtubs and shower trays as well as other conductive parts should be retained.

High voltage lines, overhead lines, rails

Main articles: electrolytic corrosion , railway power , high voltage pylon , overhead line

Norms

Main earthing rail in a building
  • DIN VDE 0100-200: 2006-06 Construction of low-voltage systems - terms
  • DIN VDE 0100-410: 2007-06 Construction of low-voltage systems - Protective measures - Protection against electric shock
  • DIN VDE 0100-540: 2012-06 Installation of low-voltage systems - Selection and installation of electrical equipment - Earthing systems, protective conductors and protective equipotential bonding conductors
  • DIN VDE 0100-701: 2008-10 Setting up low-voltage systems - Requirements for production facilities, rooms and special types of systems - Rooms with a bathtub or shower
  • DIN VDE 0100-702: 2012-03 Construction of low-voltage systems - Requirements for production facilities, rooms and systems of a special kind - Pools of swimming pools, accessible water pools and fountains
  • DIN VDE 0100-705: 2007-10 Construction of low-voltage systems - Requirements for production facilities, rooms and special types of systems - Electrical systems for agricultural and horticultural production sites
  • DIN VDE 0100-710: 2002-11 Installation of low-voltage systems - Requirements for production facilities, rooms and special types of systems - Medically used rooms
  • DIN EN 60728-11 VDE 0855-1: 2011-06 Cable networks for television signals, audio signals and interactive services; Security requirements
  • DIN EN 60079 (VDE 0165): Equipotential bonding measures in potentially explosive areas

See also

literature

  • Werner Hörmann, Bernd Schröder: Protection against electric shock in low-voltage systems - Comment from DIN VDE 0100-410 (VDE 0100-410): 2007-06. VDE series of publications Volume 140, VDE-Verlag, Berlin, ISBN 978-3-8007-3190-9 .
  • H. Schmolke, D. Vogt: Equipotential bonding, foundation earth electrodes, risk of corrosion. VDE series of publications - standards understandable. Vol. 35, 6th edition. VDE-Verlag, Berlin 2004. ISBN 3-8007-2787-0

Individual evidence

  1. ^ Wilhelm Rudolph: VDE series 39; "Introduction to DIN VDE 0100", electrical systems in buildings. 2nd Edition. VDE Verlag GmbH, Berlin and Offenbach 1999, ISBN 3-8007-1928-2 , p. 151.
  2. ↑ Hensel [1] Protection against electric shock
  3. ↑ Dr.-Ing. Bodo Appel: How incorrect earthing leads to corrosion in water pipes. , In: Haustec.de, January 25, 2018
  4. ↑ Geberit Plumbing Planning Manual , valid from January 1, 2016, or "The Geberit" planning manual - Planning with Geberit products , p. 16
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