Installation
Earthing & Protection Systems
Earthing decides whether surge energy goes safely to ground or through your equipment. We install, bond and measure earthing systems for medium-voltage installations across South Africa.
Earthing is the part of an installation that is invisible when it is right and catastrophic when it is wrong. It protects personnel from touch and step potential, and it gives surge energy a low-impedance path to ground instead of a path through the equipment.
South Africa has some of the highest lightning ground flash densities in the world, particularly across the Highveld. An arrester with a poor earth is barely an arrester at all.
What earthing and protection covers
- Earth electrode installation and testing
- Earth resistance measurement and verification
- Equipment and structure bonding
- Surge arrester installation and earth lead routing
- Secondary circuit earthing
- Touch and step potential considerations at the structure
What matters in practice
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Earth lead length changes everything
A surge arrester with a long earth lead has a much reduced protective margin. Every additional metre of lead adds inductive voltage during a surge event.
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Measured, not assumed
Earth resistance is measured on site. Soil resistivity varies enormously across South Africa, and a design assumption is not a measurement.
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Bonding prevents potential differences
Equipment and structures bonded together cannot develop a dangerous potential difference between them during a fault.
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Seasonal variation
Earth resistance measured at the end of a wet season is not the resistance you have in September. Design allows for the dry-season figure.
Related services
Need earthing designed or tested?
Tell us what you need and where the site is, and we will scope the work and quote it.