integrated characteristic of the distribution system, which assigns availability or absence of earthing of live parts of a power source, availability of earthing of exposed-conductive-parts of an electrical installation or an electrical equipment, availability and performance of electrical connection between earthed live parts of the power source and exposed-conductive-parts
Note 1 to entry: The characteristic «type of system earthing» determines special requirements to all elements of the distribution system. For components of the distribution network this characteristic determines following requirements:
– for the power source – presence or absence of earthing of its live parts. If the power source has the earthed live part the additional earthing of conductors connected electrically with the earthed live part of the power source may be provided in the distribution network. If the power source has live parts isolated from the earth the distribution network conductors, as a rule, should be isolated from the earth or, as an exception, some conductor can be earthed through an impedance;
– for the distribution line – requirements to the arrangement of the protective, neutral, mid-point and earthed line conductors.
For the electrical installations or the electrical equipment this characteristic determines requirements to earthing of the exposed-conductive-parts, and to presence or absence of an electrical connection of the exposed-conductive-parts with the earthed live part of the power source. |