I have been asked to upgrade a fuse board, however, when I did an initial visual inspection, I noticed the main earth from the DNO is unsheathed (TN-S), it’s strands that are clearly ancient!
I haven’t yet carried out any tests. Should I get the DNO to change the earth? Will they actually bother changing it? A new smart meter has recently been fitted and the tails were upgraded - should they not have replaced the earth then?
This picture shows the MET - the other cable is main bonding.
Any thoughts?
E20B2D41-8D2D-4374-8AAE-1BB43C09305A.jpeg
 
Cosidering it the main earth from the dno which is nowt do with you .
And all test are good for Ze then i would get some green and yellow. Tape on the main earths to show any body cuting it off and a sign earths connection do not remove .
[automerge]1568504892[/automerge]
You also said a smarta## meter has been fitted is their a islolator near the main cut out ,other wise the tooth fairy needs to pull the main cut out .
 
Last edited:
Cosidering it the main earth from the dno which is nowt do with you .
And all test are good for Ze then i would get some green and yellow. Tape on the main earths to show any body cuting it off and a sign earths connection do not remove .
[automerge]1568504892[/automerge]
You also said a smarta## meter has been fitted is their a islolator near the main cut out ,other wise the tooth fairy needs to pull the main cut out .
There has been an isolator fitted yes so no need to touch their stuff...
 
This is perfectly normal, it's a bare cable soldered to the service cable lead when that was installed. The CSA is usually smaller than you would choose today but in practice invariably meets (and well exceeds) the minimum required to satisfy the adiabatic, in which case it's fine. The leccy doesn't care whether it's green & yellow. In some countries bare main earths are standard practice today, they cannot be mistaken for anything else and any damage is easily visible.
 
I have been asked to upgrade a fuse board, however, when I did an initial visual inspection, I noticed the main earth from the DNO is unsheathed (TN-S), it’s strands that are clearly ancient!
I haven’t yet carried out any tests. Should I get the DNO to change the earth? Will they actually bother changing it? A new smart meter has recently been fitted and the tails were upgraded - should they not have replaced the earth then?
This picture shows the MET - the other cable is main bonding.
Any thoughts?View attachment 52157

Do a quick ze test. If it's a good earth I'd sleeve it and use it. If not then get the dno involved
 
You could ferrule the two multiwire terminations at the MET (526.9.1), I imagine you'd need to use the uninsulated variety to get sufficient length so as to maintain two terminal screws per termination, as an insulated ferrule would be too short and restricted by its insulation.
 
You could ferrule the two multiwire terminations at the MET (526.9.1), I imagine you'd need to use the uninsulated variety to get sufficient length so as to maintain two terminal screws per termination, as an insulated ferrule would be too short and restricted by its insulation.
similar thoughts. could just be tidied up a bit. no need for ferrules though as it's 7 strand, just give it a bit of a twist.
 
This is perfectly normal, it's a bare cable soldered to the service cable lead when that was installed. The CSA is usually smaller than you would choose today but in practice invariably meets (and well exceeds) the minimum required to satisfy the adiabatic, in which case it's fine. The leccy doesn't care whether it's green & yellow. In some countries bare main earths are standard practice today, they cannot be mistaken for anything else and any damage is easily visible.
If it all checks out ok - I will change the earth from the MET to my new fuse board to a proper one anyway..
 
If it all checks out ok - I will change the earth from the MET to my new fuse board to a proper one anyway..
good move. the DNO provided earth will outlast me and probably you as well. sometimes the old school solutions are best. ( now where's my wind-up Megger?).
 
The service cable needs terminating, there should be a cover over the cable end at the bottom of the cut out. In effect the cable is single insulated. DNO would upgrade main earth at same time.
 
The service cable needs terminating, there should be a cover over the cable end at the bottom of the cut out. In effect the cable is single insulated. DNO would upgrade main earth at same time.

The service cable is terminated and appears to have a heat shrink breakout boot fitted so the cable is in effect not single insulated.
 

OFFICIAL SPONSORS

Electrical Goods - Electrical Tools - Brand Names Electrician Courses Green Electrical Goods PCB Way Green 2 Go Pushfit Wire Connectors Electric Underfloor Heating Electrician Courses Heating 2 Go
These Official Forum Sponsors May Provide Discounts to Regular Forum Members - If you would like to sponsor us then CLICK HERE and post a thread with who you are, and we'll send you some stats etc

Advert

Daily, weekly or monthly email

Thread starter

Joined
Location
Broxbourne
If you're a qualified, trainee, or retired electrician - Which country is it that your work will be / is / was aimed at?
United Kingdom
What type of forum member are you?
Practising Electrician (Qualified - Domestic or Commercial etc)

Thread Information

Title
Should I get the main earth changed by the DNO?
Prefix
UK 
Forum
UK Electrical Forum
Start date
Last reply date
Replies
16
Unsolved
--

Advert

Thread statistics

Created
Snailspark,
Last reply from
Percyprod,
Replies
16
Views
5,724

Advert

Back
Top