Recommendation that is Practically a Requirement

As a child, my father would always insist that all appliances be unplugged when we were away from the house longer than a day. And if a storm was overhead, we’d be sent about the house to unplug everything – save for the TV. The TV was apparently worth the risk.

The risk, as he explained to this once-child, was lightning. Lightning that could strike the building and use the entire circuitry as a playground to dance throughout, burning up anything within it along the way.

Thankfully, we never did get hit. But nonetheless, it stuck with me: in a storm, everything gets unplugged. Save for the TV, of course.

I’m reminded of this by the 18th Edition, which comes with a much deeper acknowledgement of – and recommendation for – surge protection devices (SPDs). This is a good thing and, arguably, is long-overdue.

As many as 300,000 lighting strikes hit the ground across the British Isles every year. And as many as 60,000 of them have been known to occur in just one day – and 15,000 in just 4 hours!

A large part of this new recommendation includes a map of the United Kingdom, detailing the results of lightning strike data across the country. It came as no surprise to see my home town in a high flash density area. This forms one part of the new risk assessment method. The other two components being the distance from the transformer, and the environment (that is, urban or rural).

There are also a few conditions that, if met, means an SPD is required. If the lack of one can cause injury, death, interruption of services or activity, or affects a large number of people, then an SPD should be provided. If the building somehow doesn’t meet these conditions, then that full risk assessment needs to be carried out to prove that an SPD is not necessary.

But here’s the rub. The time and cost associated with properly carrying out that risk assessment will potentially outweigh the cost of simply supplying SPDs anyway. And if the result of the risk assessment indicates that an SPD is needed after all, it’s time and money wasted. So there it is: technically, an SPD may not be required if you can prove it. But that’s undesirable to the point that it may as well be.

The 18th edition even addresses this directly, saying “If the risk assessment is not performed, the electrical installation shall be provided with protection against transient over voltages, except for single dwelling units where the total value of the installation and equipment therein does not justify such protection”.