45A seems a bit on the light side

i would use a 50A mcb in the existing CU with 16mm twin and earth

10mm on 45A sounds ok it dpends on exactly how much each appliance draws

also if your wylex board only has a 63A main switch then you  should not fit any breakers above 32A

you can henly into the tails and i will post the procedure below but the new board should be close to the henlys and should be wired in with 25mm tails

jaja, I strongly recomend getting some advice on this from an electrician if you are not electricaly minded, it is not a minor job, you will need to properly assess maximum demand of each of them circuits, also having BS 3036 semi enclosed fuses will create problems.

I am presuming you have to have these electricaly heated system, electrical heating systems are very expensive to run, and waste alot of electricity, but if gas central heating system is not an option then ok.

If you can properly assess all that is needed then there is no problem, but I cannot recomended doing this yourself.

[quote author=L.Spark  link=1089194736/0#5 date=1089216007]jaja, I strongly recomend getting some advice on this from an electrician if you are not electricaly minded, it is not a minor job, you will need to properly assess maximum demand of each of them circuits, also having BS 3036 semi enclosed fuses will create problems [/quote]
Can I reinforce what's being said here?

I was a pretty competent DIYer before last year, a qualified and experienced electronics engineer and all that, so what could some simple electrickery teach me? Hell, I knew red was live and black was neutral, and the funny green and yellow wire was earth - it don't get any more complicated than that does it? I thought I would get a tick in the box by acquiring my 2381 certificate (which I have). Hell, I was unemployed at the time and this was a tyre-kicking exercise that seemed like a good idea.

The one thing 2381 taught me above all else is that I'm not the dogs reproductive assets I thought I was. Previously I'd have been up for a full rewire and so on, but 2381 taught me no way, best left to the professionals. I really had no idea what TT, diversity and other terms meant for example.

These days, even though I could do many of the jobs myself and have done in the past, I'm very happy to pass on work to others who have been at the sharp end long enough to know how to do things properly. I'll do the occasional change of a broken 13A socket, install a loft light and replace a light fitting, but aside from that I consider it out of my domain.

Andrew

[quote author=plugwash  link=1089194736/0#4 date=1089215330]adding a shower CU is not rocket science but you must work carefully and make the connections well [/quote]
Sorry about my blatant honesty which is known to take no friends, but I do feel this is out of the league of a DIYer because the end result could be a limp expired body lying on the shower floor.

This ain't a job I would take on - even in my own home, even though I believe I am more than competent to do the job.

Water and electricity don't mix, and especially if there is a moist body in the vicinity. I wouldn't want that moist body to be one of my family, or that of someone I know (Tony Bliar excepted).

So you do this super-duper wiring job. Great, wonderful, excellent news! Now what are you going to test it with to make sure it's safe? Everything is earthed right? Everything bonded equipotentially? The fault current is definitely gonna trip that connection if there's any stray current isn't it? Your RCD's are actually working within specification aren't they? You do have the 16th edition testing kit to hand and know how to use it?

There are too many variables in this situation for my liking.

Andrew

Apologies, I discovered that soapbox mode got inadvertently switched on......

Andrew