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ground (wiring) (GND)

Grounding or earth (GND) is used to ensure that devices, installations and systems are free of potential. It represents an electrical connection with the earth electrode and thus with the ground. This connection provides contact protection for persons (VDE 100) and a clear reference potential for the shielding of active and passive components.

For grounding, a distinction is made between protective grounding and system grounding, which are connected to each other at a central ground point. Protective grounding is used to protect people. It is at ground potential in low- voltage networks. The protective earth is intended to prevent inadmissible touch voltages from occurring at operationally non-voltage-carrying conductive system parts in the event of a fault.

The system ground provides all cable shields with a uniform shield potential. A reduction of the radiation values is possible by consistent meshing of the grounding, which means that both ends of the cable must be grounded. If only one side of an STP cable is grounded, ground unbalance occurs and the shielding of the cable is no longer effective at a length of 1/10 of the working wavelengths. At a transmission frequency of 10 MHz, the wavelength is 30 m, the cable is only 3 m long. Electrical influences interfering with the data transmission can flow off against ground via the cable shield.

The system ground is connected to the central ground point of the building, the earth electrode. From there, it is routed in a star configuration to the individual floor ground points.

Informations:
Englisch: ground (wiring) - GND
Updated at: 17.11.2009
#Words: 244
Links: connection, electrode, ground, shielding, active
Translations: DE
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