Lightning Strike Blows Substation Surge Arrester
You would be forgiven for thinking this is a story of disaster – far from it in fact. During initial test energising at a new substation in the south of England, a Tridelta surge arrester supplied by PACE Networks was found to have failed during initial site energisation tests. PACE and Tridelta technical engineers visited the site in the following days to inspect the remaining surge arresters. Together with Scottish Power engineers, it was concluded that the most likely cause of failure was a substation software issue which created a dc fault current meaning that the surge arrester had to absorb unprecedented levels of energy over a very short space of time. Two surge arresters were found to have suffered in excess of 200 strikes and in doing so saved other equipment from failing. This was equivalent to more than 5 times the expected number of strikes over the equipment service life.
Thankfully Tridelta were able to supply replacement units in a matter of just a few weeks, which enabled the substation energisation project to continue with minimum disruption.