A main switchboard has been relocated.
The new main switchboard and mains will comply with current standards.
However the main earth is water pipe earth and may or may not need extended by a meter or two to reach new msb
Only the new work must comply with today's standards however
Must the new msb have an up to date earth electrode or because its an existing installation is the water pipe ok as the part has not changed. I can't find anything that mandates this
And if the existing main earth is long enough for new switchboard location or if it needs extending will this change anything ( apart from the new peice of earth needing to be green/yellow)
Of course better practise to install new electrode but this is commercial site in the city and its not easily possible.
Feedback appreciated.
Existing water pipe earth
Re: Existing water pipe earth
An existing electrode can be re-used. No requirement to upgrade.
ESR 73A requires a check that a "main earthing system" exists.
It doesn't require the electrode to comply with modern rules; just that there is one.
But given the risk that the pipe may have been partially replaced with plastic; worth checking it's still effective.
There are several methods in "3017"; but simplest is EFLI test A-E.
For the MEC; check that the existing part is suitably sized .
There's no specific requirement to upgrade if the mains size is increased;
but ESR 13 says that whatever we do mustn't adversely affect the safety of the rest of the installation.
and some Inspectors will argue that means the MEC has to be upgraded to match.
If that's OK; then the MEC can be extended; no problem.
Permanent-type join; eg crimp, is perfectly fine.
Anything that could be disconnected by mistake should be avoided, and if used should have a electrode-type "do not disconnect" label.
Lots of people think that MECs can't be joined; but that's a myth
These days MECs must run "in as direct a manner as possible" [5.5.1.1]; but that only applies to the new bit you install.
ESR 73A requires a check that a "main earthing system" exists.
It doesn't require the electrode to comply with modern rules; just that there is one.
But given the risk that the pipe may have been partially replaced with plastic; worth checking it's still effective.
There are several methods in "3017"; but simplest is EFLI test A-E.
For the MEC; check that the existing part is suitably sized .
There's no specific requirement to upgrade if the mains size is increased;
but ESR 13 says that whatever we do mustn't adversely affect the safety of the rest of the installation.
and some Inspectors will argue that means the MEC has to be upgraded to match.
If that's OK; then the MEC can be extended; no problem.
Permanent-type join; eg crimp, is perfectly fine.
Anything that could be disconnected by mistake should be avoided, and if used should have a electrode-type "do not disconnect" label.
Lots of people think that MECs can't be joined; but that's a myth
These days MECs must run "in as direct a manner as possible" [5.5.1.1]; but that only applies to the new bit you install.