3.5 Earthing conductors
3.5.1 Minimum size of earthing conductors
3.5.2 Materials for earthing conductors
3.5.3 Mechanical protection of earthing conductors
3.5.4 Materials for earthing electrodes
3.5.5 Test links
3.5.6 Earth fault currents
3.5.1 Minimum size of earthing conductors
Earthing conductors should have sufficient cross-sectional area and mechanical strength to be capable of carrying, without sustaining damage or deterioration, any currents that may reasonably be expected.
3.5.2 Materials for earthing conductors
The material for earthing conductors should be suitable for site conditions.
3.5.3 Mechanical protection of earthing conductors
In locations controlled by an electricity entity and where a suitable enclosure prevents unauthorised access, the following apply:
- the entity should effectively protect an earthing conductor against mechanical damage to a height of 2.4m above ground level; and
- where the earthing conductor is installed below ground level, it should be buried to a minimum depth of 0.5m. Where necessary, this can be done by installing the earthing conductor in a channel chased in the rock and covered with concrete at least 50mm thick.
3.5.4 Materials for earthing electrodes
Earthing electrodes should be made from metals that will not be materially affected by any corrosive or other adverse influences.
3.5.5 Test links
If test links are inserted in earthing conductors connected to earthing electrodes, the test links should be arranged so that the opening of any one link does not interfere with earth connections, other than the one under test.
Links should not be installed in a SWER earthing system.
3.5.6 Earth fault currents
Earthing electrodes should be capable of carrying, without sustaining damage, any earth fault currents that may reasonably be expected.
Last updated July 21, 2005
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