TT supply question

[Blenh1em]

Hello Chaps

On the outside wall of the house we have TT supply with an earth rod supplied by EDF as a temporary supply for building work. Now the house is nearing done we have been told after 15 weeks that we can just use the TT system rather then pay for them to put in there norm.

I understand the obvious rcd issues i'll have with the CU but just out of curiosity as ive never used a TT, what is the small looking cable made up of that comes into our 100A fuse at the supply - obviously no earth but it feels like single solid 25mm core?

Im sure its any easy answer for most of you but ive never come across it before.

Also am i just better forking out for the standard household supply?

 

[kkynaston]

I'm not a spark but I guess that you have PME available, but as it was a building site when they put it in, they had to TT it. I think it is a regulation of building sites.
They should provide PME on it now if you show that your bonding is up to scratch

Can you post a pic of the supply

 

[securespark]

The cable is probably straight con- a central core (line) and an outer of bare copper conductors which is the PEN conductor.

 

[Blenh1em]

Thanks for the reply kkynaston, ive always had a TT on new site then had meter relocated and normally they changed it to PME etc, but as we dont need it moved they are telling us to use it if we want.

Im sure they can put in a PME but at a cost and lengthy wait, as the clients are wanting cert and to finish asap EDF said to use the TT which i found very odd.

Just want to know really how the TT is made up? im assuming id need to run 25mm tails from the meter to CU if over 3m id bung in a fused isolator

 

[Blenh1em]

Thanks securespark thats what i needed to hear, the developer im working for is possitive its just the same as a bit of 2.5 3 core flex ..... so maybe ill let him install that back to the CU from the meter.

Said to him just what you said basically but id prefer to run 25mm from the supply to the CU or fused isolator if over 3m and his answer was "thats huge though"

 

[RF Lighting]

This is straight con cable:

It looks 'thin' but it actually has quite a high current carrying capacity.