Split Power after electric company fuse & before cons

[Invisible-Man]

Hi all,

I have a new granny annexe which I have run 16mm 2 core SWG to and has it's own consumer fuse box and earth.

I was wondering how I should wire this up to the main property (feed), I wish to fuse the 16amp spur safely but as high as possible, what fuse size would be appropriate 60amp/80amp and how should this be set up correctly, (obviously can't be connected into the existing fuse box because of the fuse rating).

I have a 100amp fuse in the main property and thought that I could split the original tails in a henley block with maybe a 100amp double pole isolator along with a suitable fuse, if this would be the correct procedure could anyone recommend the parts that I would require.

Any help on the correct procedure would be greatly appreciated.

Many thanks, Martin

 

[Maxxy]

Sounds to technical to be a DIYer's post lol.
Whats your maximum demand of the main property? Have you checked first to see what spare power you've got?

 

[Adam_151]

What type of supply earthing do you have?
Whats your Ze?
Whats the R1+R2 of the cable you have installed?
Whats the expected load of the submain?

 

[Invisible-Man]

Sounds to technical to be a DIYer's post lol.
Whats your maximum demand of the main property? Have you checked first to see what spare power you've got?

Hi, I have not checked the max demand on the main property but surely if everything is protected by a 100amp fuse then the worst that would happen is this would blow and I would have my answer.

 

[Invisible-Man]

What type of supply earthing do you have?
Whats your Ze?
Whats the R1+R2 of the cable you have installed?
Whats the expected load of the submain?

The earthing in the granny annexe if thats what you mean is 16mm via earthing rod,

The expected load of the submain consists of lghting, 2 ring mains 1 being for wall heaters (3) and 1 for sockets, electric cooker, immersion heater etc.

 

[securespark]

No, Adam means what's the supply type at the origin of the circuit?

You have to do better than that re the expected load. Everything here is electric, so you may well need a 100A supply from the DNO.

Elderly folk need lots of warmth, so a dwelling without other fuel will take a lot of electricity to heat up.

Ditto water heating by immersion.

Add an electric cooker and maybe a shower, and I'm sure you'll be knocking on the door of a ton.

However, I'm afraid that if you are unfamiliar with Ze and R1+R2, not to mention Part P, then you don't have the necessary knowledge to install correctly.