Lightning protection and grounding in Bali

A complete system is three parts and they only work together. Air terminals intercept the strike. Down conductors carry tens of thousands of amps to earth without flashing sideways into wiring or plumbing. And an earth termination network disperses it into soil that has to stay conductive in September as well as January. Miss one of the three and what you have installed is an attractor. We size and bond all three, then measure the result rather than assuming it.

Protecting the structure is only half the job, and it is the half most owners are not actually worried about. Direct strikes are rare; induced surges are weekly. So the electrical side gets its own layer — a Type 1 arrester where the supply enters, Type 2 at the distribution board, and Type 3 units in front of the equipment that hurts to replace: inverters, pool controllers, network racks, the cinema.

ESE terminals and the claims around them

Walk into an electrical supplier here and someone will offer an early-streamer-emission terminal with a protection radius of eighty or a hundred metres printed on the box. We fit them when clients want them, and we say what the international standard says: IEC 62305 positions air terminals by the rolling-sphere method, and it does not recognise the enlarged radii claimed for ESE devices. Independent field studies have repeatedly failed to reproduce the marketing figures.

In practice that means one thing. Trusting a single ESE head to cover a whole compound usually leaves corners of the roof outside genuine protection, at a price above a properly laid-out conventional system. So we quote the conventional design first, set out by rolling-sphere geometry, and if you still want an ESE terminal it goes on top of a system that would work without it. Nobody should pay more for less coverage.

Why earthing fails on this island

The whole system ends at the earth electrode, and that is where most Bali installations quietly fail. Limestone on the Bukit gives high resistivity and shallow rock. Coral fill and dry-season soil push a comfortable four ohms in February to thirty by September. A rod driven two metres into hardpan and never measured is not an earthing system; it is a hopeful piece of copper.

We test with a proper earth tester before signing anything, then build to hold a stable figure below five ohms: deeper driven rods, multiple electrodes in a ring, bentonite or conductive backfill in rocky ground, and an inspection pit so the reading can be repeated in future without digging up a garden. The certificate records the value, the method and the date — which is also what insurers and hotel auditors ask to see.