Replacing long meter tails

[TodeW]

I'm in an apartment that was converted probably in the 1960s. The meter tails go down two floors and I think they are probably 7/.064. Now I want to change my gas cooker for an electric one. As we have gas CH and no electric showers I think I could get away with it on capacity. But, I also want to replace the 1970s fusebox with a modern CU. I know replacing the tails will be a difficult and expensive job as they go through the other apartment, but it seems the right thing to do when I am having other work done.
So, if I dig into my wallet and do it, what size? Should I, or must I, go to a size that will run a heat pump? Even though at present there is no way to fit one in the apartment?
And should I take account of the size of the incoming supply? I don't know what it is, but I'm pretty sure that one supply runs two apartments each with two floors and to my knowledge has not been changed since 1974, maybe even earlier.
I have a background in electronics so I have a basic understanding, but obviously I need an electrician for this work. I will of course take a professional's advice but it would be very useful to have some ideas before I start discussions with tradespeople.

 

[Murdochcat]

You need to determine exactly what size the existing tails are. What size fuse are they protected by?

 

[TodeW]

I've finally managed to access the other apartment in the building, where the incoming supply is. There is a multi way fusebox supplied by one incoming cable which is apparently lead sheathed, but no fuse sizes are marked. The supply is provided by UK Power Networks but they have no records of the fuse size or the capacity of the incoming cable.
I'm beginning to think that the whole thing is too difficult and I just should get a new gas cooker or a gas oven and a hob that will run off the ring main. If the existing tails are 7/064", which seems likely from the outside dimensions of the cable, they're more than adequate for the present use, with reasonable diversity. But I fear they wouldn't be adequate with an electric cooker as well even if its circuit only had a 32 A breaker.

 

[flameport]

But I fear they wouldn't be adequate with an electric cooker as well

Why not?
7/.064 is approximately 16mm², good for 60+ amps in most installation methods.
With gas heating, just how much electrical load do you expect to be using?

 

[Luckyphil]

If the existing Tails are a suitable size &
In good condition , I’d look at running them
Into a Henley Block in your Flat & run 25mm tails from there into the new Consumer Unit

Regards
Phil

 

[TodeW]

Thanks Phil. Not doubting your advice but I'd love to know what is the benefit of adding an additional connector into the system.

 

[EFLImpudence]

If the existing Tails are a suitable size & In good condition , I’d look at running them
Into a Henley Block in your Flat & run 25mm tails from there into the new Consumer Unit

Why?

 

[SUNRAY]

If the existing Tails are a suitable size &
In good condition , I’d look at running them
Into a Henley Block in your Flat & run 25mm tails from there into the new Consumer Unit

Regards
Phil

The only reason I can think for doing this would be due to the lenght not easily reaching the new CU, if that were the case I'd be looking at an isolator which will be handy when the CU needs changing again as the electrical fashions move along.