1.0mm

I am planning a rewire on a 4 bed older style house ,and find I can get very reasonably priced
3-core + earth cable(2way switching -red ,blue ,yellow and bare)
and also switching cable (twin+earth- red -bare-red)
Thing is, both these are only available on 1.0 mm guage.
Is this legal assuming the supply runs will be in 1.5mm?

Also I plan to have the existing meter changed ,and as this is being done ,have the main supply wired into a switchfuse then to the consumer unit.
I have had this done before and is really useful for the DIYer.
I have used a MEM 800KMF before (this was in 1995) and wondered if this would still be OK in mainland 2003 Britain.

It depends where you look for your cable, try here for 1.5mm twin and earth.

As for being legal, it doesnt matter, what does matter is is it safe, 1mm used to be the norm for lighting but now 1.5mm is, but 1mm is still fine (so long as you do not over load it, which is highly unlikely)

I do not understand why you would want to be able to isolate your consumers unit, so long as you turn the main switch off and do not touch the incoming cables you will be o.k. and as you are having a new meter, why not get a new consumers unit with an rcd as well

Thanks for the reply breezer.
My reasons for a switchfuse are not immediatly apparent.
By putting one in you can isolate the consumer unit completely and therefore actually remove it, -all without the hassle of calling in electricians or electricity board.
I will be undertaking a complete rewire whilst living in the property.As I also work full time (and then some! ) it all has to be done bit by bit, circuit by circuit.This includes the old fusewire distribution board.
The whole system is 1960s vintage and it all has to go as a condition of the mortgage.
Which brings me on to the cable size.
DIY rewiring isnt illegal but the Lender or a subsequent purchaser may require a certificate.Although I am more than capable of doing the work Im not officially qualified so I cant provide the documentation
I would need an inspection by a chap whose got the sacred piece of paper.My point is;would there be an objection to the use of 1.0mm?

Thanks for the screwfix link but they also only do the special purpose cables in 1.0.
Any advance on this??

I would be surprised if an electrician does pass it with a break between the meter and consumers unit, but i may yet be surprised.

Three core and earth is only made in 1mm (and before some one says it , yes, you can get it bigger, but wire armoured, which is not what you require)

Re: 3 core and earth in 1.0mm, you can get it in 1.5mm PVC (not wire armoured) ...City Electrical Factors sell it. As for the main switch between the meter and consumer unit ... Scottish Power install this in new installations, they will also do it if asked to pre-existing installations usually at a charge, it's not fused tho' it's a 100 amp DP switch. The top side is sealed by them but the bottom side is not and it is an ideal way of completely isolating your consumer unit ...especially if you intend working on it.

Thanks all
Ive done some more digging and it would appear that the Holy 16th makes no issue of using 1.0 mm as long as the voltage drop/current/ loading shebang isnt abused, ie in an excessivly long and loaded run.

I only plan to use the specialist-colour cored 1.0mm to run to the switches from the loops and j-boxes , and then use 1.5 for the supply runs
It would all seem to be OK.

The thought of wiring a 2gang 2way switch in a plaster depth box using nice chunky 1.5 cables is just too nasty to contemplate.........

Alexnic-you wouldnt have a part or model number for the isolater??????

Sory Evdama I don't, but it's an MEM Double Pole Single Phase 100 amp Isolator so it shouldn't be too hard to find from their catalogue

The general idea is that you use 1.5 for your lighting ring but the 1.0 for the switches, although under normal circumstances, with normal folk, i.e. dont put ya fingers in light socket while showering ( lowest common denominator ) 1.0 should do the trick. if you add up the possibility of all lights being on at once, plus a bit for the new lights you will (eventually) want to fit, work out amperage, compare to cables current/amperage capacity (on these hallowed pages) (kw/volt = amps)

I came across the same problem recently and I realized that while the cable used for wiring the lights in series carries the total load of all lights in use,the 3 core cable is used only for the two way switches and carries only the load for the light involved so 1 mm is more than adequate.ie up to 1200 watt