The Regulations for the Electrical Equipment of Buildings, 13th Edition, 1955 regarding P.M.E. supplies required that provision be made for the installation neutral to be connected to earth continuity conductor at the origin of the installation by the supply undertaking. (Reg. 409). Where a P.M.E. supply was to be used the regulations said, compliance with Clause C was "desirable" as "an added precaution." This meant that the installation was to have its own earthing electrode. A solid metal to metal buried water pipe system was suggested as an earth electrode but metal gas pipes were prohibited for use as such. A note mentions the increasing use of non metallic water pipes.
So, back then with a P.M.E. system, an additional installation earth electrode was recommended as an added precaution..
What happened to that requirement?
Note. The 14th Edition (1966) forbade the use of public gas and water service pipes as the SOLE earth electrode of an installation. (D 35). But was the need for an approved consumer's independent earth electrode done away with in P.M.E. systems.? And why?
Z.
