Project Lumen: Lightning protection innovation
By T Manas, Pontins
Electricity+Control, April 2015 (pages 15 - 19)
Enquiries: Trevor Manas email: email@example.com
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Project Lumen is the world’s largest light emitting display. This world first is located approximately 140 m above the Johannesburg skyline on top of the ABSA Towers building and is an instantly recognisable landmark. The screens dubbed ‘Lumen’ are bigger than those that make famous London’s Piccadilly Circus and New York’s Times Square. Lumen uses the most advanced LED technology on such a large scale making it a world first.
Project Lumen comprises four giant LED displays, each almost twice the size of a basketball court (40 m long, 18 m high). These can be seen from many kilometres away. Since being ‘switched on’ in November 2013, the LED screens have been continually damaged by direct lightning strikes owing to various factors like Johannesburg’s high lightning density (11,7 strikes per km² per year), the height of the LED screens (138 m) and the susceptibility of the technology to lightning damage.
Lumen was equipped with a lightning protection system using the old ‘cross bonded’ protection method. There was no separation distance between the lightning protection conductors and the LED panels or the electrical or data supply cables to the panels. This resulted in the entire LED system being vulnerable to partial lightning currents which then caused substantial damage to the LED system.
The solution to the problem was to install an ‘Isolated’ lightning protection system where the lightning protection conductors are separated or isolated from the LED screens and frames.
- The LED system installed in ‘Project Lumen’ was vulnerable to partial lightning currents.
- The solution was to install an ‘Isolated’ lightning protection system.
- The HVI power conductor was suitable for the Project Lumen’ installation.’