ART815650.book Page 76 Lundi, 6. février 2006 10:18 10
Earth : the conducting mass of the Earth, whose electric potential at any point is conventionally taken as zero.
Earth electrode : conductive part that can be incorporated in a particular conductive environment, for example concrete or coke in electrical contact with earth.
Earth-fault current: current flowing to earth due to an insulation fault.
Earthing resistance or in fact the "overall earthing resistance" : resistance between the main earthing terminal (terminal or bar to which the PE protective conductors are connected) and earth.
Earth-leakage current : current flowing from the live parts to earth or extraneous conductive parts in the absence of an insulation fault.
Equipotential bonding : electrical connection putting various exposed conductive parts and extraneous conductive parts at a substantially equal potential.
Exposed conductive part : a conductive part which can readily be touched and which is not normally live, but which may become live under fault conditions.
Intentional leakage current : current flowing to earth or extraneous conductive parts via intentionally installed components (resistors or capacitors), in the absence of an insulation fault.
Isolated system: system with an autonomous supply of power, not connected to utility power.
Natural leakage current : current flowing to earth or extraneous conductive parts via the insulation, in the absence of an insulation fault.
Protective conductor PE: a conductor required by some measures for protection against electric shock for electrically connecting any of the following parts: exposed conductive parts, extraneous conductive parts, main earthing terminal, earth electrode, earthed point of the source or artificial neutral, metallic parts of the building structure that are not part of an electrical device, protected by equipotential bonding, if they are simultaneously accessible.
Residual current : vector sum of the instantaneous values of the current in all the live conductors of a circuit at a given point in an electrical installation.
Zero volt (reference): measurement reference point for differences in potential
(voltage measurements, often in monitoring circuits).
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