No main earth in domestic supply

[P&Q]

Hi everyone,

I got called in by a customer to install a new circuit for their cooker in the kitchen. So I went over and looked at the main supply and there was no earth. So I told them to get in touch with their supplier and ask about this missing main incoming earth cable and what is the Earthing system, and this afternoon he got back to me, and Scottish Power had simply said, some houses have earth and some really old ones don't - all they have is a Phase and a Neutral cable, and that's it and they're not gonna do anything about it.

I was just wondering, what the deal is with is, should I get back to them myself, or even set up a TT system myself?

Appreciate any advice in advanced guys

 

[Geordie Spark]

Hi everyone,

I got called in by a customer to install a new circuit for their cooker in the kitchen. So I went over and looked at the main supply and there was no earth. So I told them to get in touch with their supplier and ask about this missing main incoming earth cable and what is the Earthing system, and this afternoon he got back to me, and Scottish Power had simply said, some houses have earth and some really old ones don't - all they have is a Phase and a Neutral cable, and that's it and they're not gonna do anything about it.

I was just wondering, what the deal is with is, should I get back to them myself, or even set up a TT system myself?

Appreciate any advice in advanced guys

This is exactly the same as the house I'm working on - except that we have a bit of 6mm green & yellow connected to the earth bus at one end & wrapped around a central heating pipe under a bedroom floor at the other, and that's all.

When I've finished the job, it will be TT & have a High Integrity board and a full rewire with 10mm bonding to the gas, water & central heating.

I'm also fitting a double pole isolator in the tails between the meter & the new board to save chopping the seal & pulling the main fuse in future.

 

[Engineer54]

Better first to find out if the DNO can PME the supply!!! If so, far better than you bunging a rod in the ground!!!

 

[mcummins7]

Someone's been in to connect an earth to the gas pipe? When did that happen? I suggest that you've never seen a TT system, missed the earthing that was present, ie., the earth electrode rod outside the front or back door including the main protective bonding to the gas and water and that the dwelling was absolutely fine.

 

[SimpleSimon]

Someone's been in to connect an earth to the gas pipe? When did that happen? I suggest that you've never seen a TT system, missed the earthing that was present, ie., the earth electrode rod outside the front or back door including the main protective bonding to the gas and water and that the dwelling was absolutely fine.

No offence but I think your jumping the gun a bit 'suggesting' the OP has never seen a TT.
You could be right and the he may have missed the rod outside but it doesn't mean he's never seen one before.
Remember a gas pipe can be used as a earthing point IF it is privately owned.
We Havnt got enough info here to know if that could even happen at this property so I don't want to make presumptions.

 

[G.W.Electrics]

scottish power dont have to supply an earth easiest soloution earth rod out side into property with apropriate cabling should provide decent earth

 

[Golden_Boy]

Those tests will not confirm that the main supply cable is PME.

I rang up my DNO to ask what sort of earth I should have here at home ( presently TT ) .. The answer I got was " Ask your Electrician " !!!! Stupid or what?

 

[Benny_Boy]

I rang up my DNO to ask what sort of earth I should have here at home ( presently TT ) .. The answer I got was " Ask your Electrician " !!!! Stupid or what?

Yep, most folks on here have had similar experiences when dealing with DNOs. The problem seems to be a complete lack of anyone who knows what they're talking about!

 

[andekoch]

did a job last week at a house with no DNO earth. Ze via the bonded gas and water was 0.3 ohms. Installed an earth rod and RCD though. DNO wanted £300 to put a connection from the lead sheath to the MET, customer decided to go with the cheaper RCD and rod option. Hate dealing with the DNO, too many fob offs from people who dont know what is happening.

 

[chrisreid186]

pretty sure you cant just use the main neutral conductor as a main earth conductor, as i understand it pme has a earthed neutral (DNO side) which will provide a alternative path under fault conditions , if the neutral wasn't earthed and there was a main neutral fault (although unlikely) everything attached to the met and all cpc's would become live, please correct me if I'm wrong
cheers

 

[domestic spark]

If there's no earth you can't test!

 

[malcolmsanford]

No offence but I think your jumping the gun a bit 'suggesting' the OP has never seen a TT.
You could be right and the he may have missed the rod outside but it doesn't mean he's never seen one before.
Remember a gas pipe can be used as a earthing point IF it is privately owned.
We Havnt got enough info here to know if that could even happen at this property so I don't want to make presumptions.

Sorry Simon think you mean a private water pipe and not gas pipe.

 

[SimpleSimon]

Thanks Malcolm. I thought it was either to be honest. Happy to be corrected.

 

[domestic spark]

DNO wanted £300 to put a connection from the lead sheath to the MET



how much!!!! whats that 100pound a min!!!

 

[Engineer54]

DNO wanted £300 to put a connection from the lead sheath to the MET, customer decided to go with the cheaper RCD and rod option..

So your customers DNO cable is TN-S, ...as i don't think i've seen a PME cable with a lead sheath, ...lol!!
Unlike others that have mentioned converting a supply to TNC-S. ...There is however no reason why you can't take the cables earth to the MET yourself!!! But i would check the Ze first, anything under 0.8ohm is good (even just over, at a pinch) . It maybe however, that an original earth connection has been removed at sometime by the DNO, due to the breakdown of the lead sheathing on that cable run. ...But then, ....hopefully they wouldn't then be wanting to charge 300 quid to reconnect it ...haha!!!

So check Ze first, ...all OK, take the cables readily available earthing to the MET ...Sorted, ...Lucky You, and Lucky customer!!

 

[malcolmsanford]

Engineer did I read you right there mate, are you saying you would clamp the lead sheath of a DNO cable and then run the earth conductor yourself to the MET.