Our ECA expert answers a question from a Voltimum user regarding outside conduit and BS7671 guidance.
The customer wanted an industrial type of installation for outside lights. The metal conduit is low level 2 meters and in reach.
The supply is fused from the kitchen ring RCD protected via a swa to a metal box containing the terminals for the lights and motion detectors.
During testing it was discovered that the lead sheath had a break and the DNO converted the earthing to PME. I’ve now exported a PME outside, although it is not a sub main and just an extension of the kitchen ring.
My question, how would you resolve this issue, should I install a PEN monitoring device. What guidance does BS7671 offer.