New connection direct to cabin whilst house is demolished scenario - advice required

[Torpediniforme]

Rather than have a temporary building supply my customer has agreed with Southern Electricity for them to cut and extend his current supply to a cabin at the rear of his house which is being demolished.
I am planning on installing a small CU with 30mA RCD main switch and an earth stake since there will be no gas or water to bond to, my thinking for this is so that it can also meet the requirements of a TT site supply and also for if it is fed from the CU in the new house in the future. It’s a partial self build project which could take a long time.

Re: the buried earthing conductor to the stake (a 5/8 1200), after looking at the Regs and GN’s 1 and 8, I'm a little confused but assume I need 16mm2 (even with mechanical and corrosion protection)?

My customer will install a surface mounted meter box on the front of his cabin.

Just wanted confirmation that this was the best way or not?! (Originally I was going to install a split load CU with 2 RCD’s instead of on the main switch and an earth stake)
It’s currently TNS. I’m also wondering if Southern Electric will change it to TNCS.

 

[malcolmsanford]

Re: New connection direct to cabin whilst house is demolished scenario - advice requi

Rather than have a temporary building supply my customer has agreed with Southern Electricity for them to cut and extend his current supply to a cabin at the rear of his house which is being demolished.
I am planning on installing a small CU with 30mA RCD main switch and an earth stake since there will be no gas or water to bond to, my thinking for this is so that it can also meet the requirements of a TT site supply and also for if it is fed from the CU in the new house in the future. It’s a partial self build project which could take a long time.

If you have a TN-S supply why are you wanting to downgrade it to a TT

Re: the buried earthing conductor to the stake (a 5/8 1200), after looking at the Regs and GN’s 1 and 8, I'm a little confused but assume I need 16mm2 (even with mechanical and corrosion protection)?

Assume this is an earthing conductor we are talking about .....have a look at reg 543.1.1 as you have a TN-S supply

My customer will install a surface mounted meter box on the front of his cabin.

Just wanted confirmation that this was the best way or not?! (Originally I was going to install a split load CU with 2 RCD’s instead of on the main switch and an earth stake)
It’s currently TNS. I’m also wondering if Southern Electric will change it to TNCS.

They may undeed upgrade to the TNC-S but you will have to ask them this

 

[Torpediniforme]

Re: New connection direct to cabin whilst house is demolished scenario - advice requi

Initially as there is no main bonding if there was a fault with the supply earth so thought about using an earth stake and after research because of what I have read on the bottom of page 6 of the link below - see part 3.1 - although I personally haven't found any thing specific about this in the Regs etc


electrical.------.org/wiring-matters/16/earthing-questions.cfm?type=pdf

 

[malcolmsanford]

Re: New connection direct to cabin whilst house is demolished scenario - advice requi

Sorry mate it is my age so you'll have to bear with me a little, if the DNO have agreed to transfer their TN-S supply from the house to the Cabin, even be it temporary, then they are still liable to maintain that earth for the customer.

As you said in your original post there is no gas or water services, which IMO opinion is, if not illigal for a dwelling is not very comfortable, and providing the cabin itself is not metal, there is no need for bonding anything.