Surge & Lightning Arresters
A surge arrester diverts strike energy to earth before it reaches your transformer or recloser. We supply surge and lightning arresters from 11kV through to 33kV.
Lightning arresters divert surge energy to earth before it reaches the equipment behind them. On an overhead distribution network that matters: a single direct or induced strike can take out a transformer, a recloser or a run of cable, and the replacement cost and outage time dwarf the cost of the arrester.
South Africa has some of the highest lightning ground flash densities in the world, particularly across the Highveld and KwaZulu-Natal. Surge protection is not an optional extra on exposed overhead lines here.
We supply arresters from 11kV through to 33kV, matched to the network voltage and the equipment being protected.
What they protect
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Distribution transformers
The most common and most expensive single item lost to surge damage on a rural feeder.
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Auto reclosers and switchgear
Protecting the electronics and insulation in equipment installed on exposed lines.
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Cable terminations
At the transition point between overhead line and underground cable, where surge reflection occurs.
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Substation equipment
Limiting the surge that reaches equipment inside the substation fence.
Specifying an arrester
What we need to know
Getting arrester selection right depends on more than network voltage. We will ask about the system earthing arrangement, the continuous operating voltage, the energy class required, and what equipment sits behind the arrester.
Installation matters as much
An arrester with a long earth lead protects less than the same arrester properly installed. Lead length, earthing quality and mounting position all affect the protective margin, which is part of why we prefer to install what we supply.
Tell us the network voltage, the system earthing arrangement and what you are protecting, and we will confirm the right arrester rating, pricing and availability.
Need surge protection specified?
Tell us what you need and we will come back to you with a clear quote.