Rules and Guidelines
Want to participate in the discussions? Please read our Community Rules and Guidelines. Need some help? Visit Support and Answers.

  • State Not Answered
  • Locked Locked
  • Replies 4 replies
  • Subscribers 33 subscribers
  • Views 705 views
  • Users 0 members are here
Options
You may also be interested in
This discussion has been locked.
You can no longer post new replies to this discussion. If you have a question you can start a new discussion

P.M.E. Installation Earth Electrode. Historic.

Zoomup
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.
Parents
  • 0
    Although in that case you may have expected the electrode requirement to remain for buildings with plastic service pipes.

    I was thinking that banging in a rod or similar is next to useless for coping with broken PEN conditions. Foundation electrodes might be a bit better (but possibly still not ideal especially in poor soil conditions given our relatively large single phase supplies and so potentially large N currents) - but are completely impractical anyway, especially for existing buildings. Whereas something extensive like a water distribution system might just work. So the choice boils down to service pipework or nothing - if the water is metallic you get that for free via the main bonding anyway, otherwise there's nothing that can be done. So no specific requirement need be written.


        - Andy.
Reply
  • 0
    Although in that case you may have expected the electrode requirement to remain for buildings with plastic service pipes.

    I was thinking that banging in a rod or similar is next to useless for coping with broken PEN conditions. Foundation electrodes might be a bit better (but possibly still not ideal especially in poor soil conditions given our relatively large single phase supplies and so potentially large N currents) - but are completely impractical anyway, especially for existing buildings. Whereas something extensive like a water distribution system might just work. So the choice boils down to service pipework or nothing - if the water is metallic you get that for free via the main bonding anyway, otherwise there's nothing that can be done. So no specific requirement need be written.


        - Andy.
Children
No Data

Community Rules & Guidelines