Live distribution boards pose a severe health hazard if maintenance is carried out unsafely, as the HSE report into a flashover incident demonstrates.
In December 2011, two workmen were replacing capacitors on a distribution board just a few inches above the live busbars housed inside it.
As they manoeuvred the capacitors into position, their metal casing contacted the live conductor risers on one side, creating an electrical flashover.
This generated temperatures high enough to vaporise the metal in the live conductor, and caused severe injuries to both men.
HSE inspector Kerry Cringan said: “Live work should only be undertaken if it is unreasonable to make the conductors dead and suitable precautions are taken to prevent injury.”
The case is a reminder of the risks posed by distribution boards, particularly if they are housed in hazardous areas, and why efforts should be taken to protect workers against the risk of a flashover.
Although this is particularly the case during maintenance work on the distribution boards themselves, it is also true on a continuing basis, to avoid any incidents that could endanger employees working in already hazardous areas.