Yeah, some points, here, I have installed three of these such devices, since posting the topic.
I don't really like the idea of running around to quickly unplug everything in the event of a thunder-storm.
These units that I was talking about, fit neatly into a DIN Rail type switchboard, with a link out of the load side of the main switch and into the diverter unit, from there, I normally run a 16mm2 wire to the Earth Busbar, short as possible.
People are slowly starting to realise over here that something can be done to protect their expensive computer equipment, and with our large number of lines still not under-grounded, this is very cheap insurance.
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