Main Earthing Cable

[Mark.W]

Hello Chaps

I'm upgrading a Main Earthing cable from the Electricity meter to the MET from a 10mm to a 16mm. What are the necessary steps that I need to take? I haven't done this before? Not sure whether I need to isolate the supply or if I can just unscrew the old 10mm and replace with the 16mm.


Thanks
Mark

 

[Mac]

I take it is a TNCS system.I would pull the main fuse.You would have to cut the seals first if there are any.Should be a cut out where the neutral is.Cut the seal on that and then replace the 10mm with your 16mm.You're not supposed to cut the seals but the DNO would have to prove it was sealed when you replaced the earth

 

[Guest123]

Hi.

When you say it's coming from the meter, do you mean from the cut-out i.e, is it a PME connection you have??

Before you do anything you would need to switch all MCB's RCD's and or main switches off as effectively you are removing the main earth for the installation so everything should be switched off.

 

[Mark.W]

Hi

Soz yeah it's coming from the cut-out. I have a TNS as it is Cable Sheath Earth.

Here's some picw of the system!

 

[Mac]

Hello Chaps

I'm upgrading a Main Earthing cable from the Electricity meter to the MET from a 10mm to a 16mm. What are the necessary steps that I need to take? I haven't done this before? Not sure whether I need to isolate the supply or if I can just unscrew the old 10mm and replace with the 16mm.


Thanks
Mark

Are you sure your taking an earth from the meterIf it is TNS,then i wouldn't touch the incomer.If there is an MET then just take your 16mm from there to the board.The DNO would have to replace the 10mm from the incomer to the MET.The glands are usually sweated on

 

[Mark.W]

No not from the meter! soz I am tired been a long day!! Its coming from the incomer to the MET, I also have no bonding in the house so I wll have to get the gas and water pipes bonded with 10mm. The cable from the MET to the earthing bar in the cu is 10mm, so do you suggest I only replace that with the 16mm and leave the 10mm from the incomer for the DNO?

 

[Mac]

Hi

Soz yeah it's coming from the cut-out. I have a TNS as it is Cable Sheath Earth.

Here's some picw of the system!

Looks pretty easy to change.Make sure you don't over tighten the clamp on sheathIf you don't want to change the earth from the incomer to the MET,just replace the one to the CU and let the DNO know that it needs changed.They will probably never change it anyway,but make a note of it on your paperwork

 

[Guest123]

You should be able to swap that over fairly simply mate.

Get your services bonded first though, much more important!!!

 

[Mark.W]

Yeah you're right it's not a difficult job, I am just wondering about isolation, do I just switch off all MCB's and RCD's in the board, or do I still have to pull the fuse? and what's the safest way of pulling the fuse? Soz for all the questoins!

 

[Mac]

Just isolate main switch at CU

 

[Guest123]

I'd leave the fuse alone, the main switch in your DB will be double pole anyway so just turn all breakers and RCD's / main switches off and you'll be fine.

 

[jambo65]

u dont need to take ure fuses out just run ure cable get everythin ready then wallop it ovr quick style, haha

 

[Mark.W]

Cheers Guys! I've never worked on a TNS before and didn't like the look of the the earch clamp, just gives me the heeeebeeeeee jeeeeeeebeeeeeees! So I'll leave the main earth from the incomer to the MET for the DNO, switch off the main switch in the CU. Change the 10mm from the MET to th CU to a 16mm and then bond all my pipes to the MET with 10mm.

When does one pull the fuse and what's the best way of doing this? I know I shouldn't break the seal, but that seal looks broken to me!

Ok Rambo!! Oh sorry that's Jambo haha

 

[Mac]

When you are doing a board change or upgrading the earth to 16mm on PME system

 

[Spudnik]

If you decide to change the main earth to the incomer to 16mm, it wont fit into the clamp.

You will need to use a ringed uninsulated crimp.

If you have no experience with these terminals then its best left to the DNO.