Hi,

I have come across HV switchgear in a recent audit that is underrated for the supply voltage. The switchgear is on a UK 11kV network, the switchgear itself is 11kV rated, as is one of the five outgoing circuit breakers. However, four of the five circuit breakers are 6.6kV rated. I am reporting these findings (along with others) and I am struggling to demonstrate the lack of compliance of this switchgear. I argue that using 6.6kV switchgear in an 11kV network is a breach in law but I can't back it with specific legislation. I can find guidance from the HSE on "overstressed" switchgear but I don't think this is really applicable (that's switchgear underrated for current fault levels, right?). I'd like to back up my statements in my report with some HSE guidance or H&S law but I am struggling.

Does anyone know of any specific legislation covering underrated HV switchgear/circuit breakers?

For more information, this switchgear is circa 1950s, oil filled and DMO (dependent manually operated).

Thanks,

Tony