Grounding and its effect
In the universe, all matter consists of atoms which seek to maintain their equilibrium electrostatic nature, i.e., an equal number of positive and negative charges. Since the mass of the planet consisting of a mixture of different substances whose atoms, taken together, seek equilibrium electrostatic this causes the land is electrically neutral.
An atom loses its neutrality when it gains or loses electrons by friction, induction or contact generating an electric field around it.
It should be borne in mind that the atmosphere surrounding the Earth also contains atoms and interacting with atoms of the earth. This phenomenon leads to some negative charges of the earth are attracted by ionosphere to making the planet slightly positive, which for us is irrelevant. Evidence of the existence of this phenomenon is the atmospheric discharges, lightning, that at any moment occurring on the planet.
Moving the man standing on the floor that makes the body normally remains at the ground electric potential. So that there can be electrical safety is necessary to ensure that whatever man can touch or handle has a grounding.
The way to achieve grounding consists in a ground electrode rod vertically buried deeply connected by a cable to the electrical bonding bar installation or directly to a lightning rod.In an installation which is either equipotential should only be a single network circuit ground.
The arresters are devices mounted on masts on top of buildings or antenna towers, grounded by a ground conductor himself to the currents of lightning have a preferred path for the land and protect the infrastructure where is installed.
In the absence of discharge currents to earth, the ground electrode is at ground potential but in the event of discharge current values of currents and earth resistance will determine the value of the potential of the ground electrode at the time of discharge and should therefore, the value of ground resistance be as low as possible to avoid having high potentials.
With the mandatory use of protective difference to the input of the electric low-voltage regime in the earth TT, it can be said that there is not a reference value for the resistance value to earth, what is required is that the its value should ensure action unequivocal differential protection against indirect contact considering a touch voltage of 50V (25V in some other countries) and a maximum current of nominal protection IΔn indicated in circuit breaker. (R(máx.)=50V/IΔn).
If the purposes of a grounding protection are the infrastructure and security of people, their functions are to dispel chains and to eliminate potential differences between different surfaces to ensure your equipotentiality.
The arresters are devices mounted on masts on top of buildings or antenna towers, grounded by a ground conductor himself to the currents of lightning have a preferred path for the land and protect the infrastructure where is installed.
In the absence of discharge currents to earth, the ground electrode is at ground potential but in the event of discharge current values of currents and earth resistance will determine the value of the potential of the ground electrode at the time of discharge and should therefore, the value of ground resistance be as low as possible to avoid having high potentials.
With the mandatory use of protective difference to the input of the electric low-voltage regime in the earth TT, it can be said that there is not a reference value for the resistance value to earth, what is required is that the its value should ensure action unequivocal differential protection against indirect contact considering a touch voltage of 50V (25V in some other countries) and a maximum current of nominal protection IΔn indicated in circuit breaker. (R(máx.)=50V/IΔn).
If the purposes of a grounding protection are the infrastructure and security of people, their functions are to dispel chains and to eliminate potential differences between different surfaces to ensure your equipotentiality.
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