3 phase domestic

Well you could have three consumer units, one for each phase which may be good as you may need to turn one off and leave the others on. Or you can install a three phase distribution board such as that shown in the link. It will be necessary to see if all of the modern gadgets that may be needed are available for your choice of board such as R.C.D.s/ A.F.D.D.s/Surge protection devices/R.C.B.Os etc.

https://www.youtube.com/watch?v=hRjTEntEqqU

And then there are these.....

www.screwfix.com/.../9696V

Z.

If you want to scare yourself off, this EFIXX video below makes a huge meal of something simple. Realistically, a 4 pole isolator like a REC 4 to give single point isolation  then feeding either 3 conventional boards or one 3 phase board fitted out with a suitable mix of single pole and 3 pole RCBOs or breakers is probably not much harder than what you do already.  But it will be a bit bigger - but it really does not need to be  that much bigger ;-)

Some thought is needed to load balance over the phases, but it does not need to be perfect. It is not a regs requirement, but it is nice not to confuse things by having more than one phase at the same light switch e.g. for up and down stairs,  but otherwise business very much as usual.

Depends on the requirements. In some WP areas I think the idea is that all the 'normal' stuff goes on one phase, anything extra - like EV charge points or heat pumps - go on another (the DNO then rotate the phases between houses to balance things out). So in that case you'd have an ordinary single phase CU as normal, plus either a small additional CU or something like a switchfuse for the other.

In other situations the idea might be to allow the use of 3-phase equipment - both EV and heatpumps come in 3-phase variants - and it might be useful for other things as well (e.g. DIY workshops that might want things with 3-phase motors). In these cases a 3-phase DB might make more sense - or you could go for a combination of a single phase CU plus some small 3-phase switchgear. As with anything new it's best to have some detailed discussions with both the customer/specifier and the DNO - as there are likely to be quite a few different assumptions floating about until some common practice gets established.

    - Andy.

Check with your scheme provider; do you require to be insured as Approved Contractor status, as opposed to a Domestic Installer for work at 415V?.  

Jaymack

It would be interesting to know the DI status, but a very large part of the planet has been supplying  all 3phases to domestic properties for years, and there is no real evidence that to do so requires any more skill or is more risky than our more common UK arrangement of single phase but  sometimes with higher PSSC.

There is a tendency  to put 3 phase installation on a pedestal as in some way more difficult, but really it is only a matter of familiarity.

Mike..

Nothing!

Don't be frightened by the 400 V phase-phase potential. Yes, the equipment is a bit different. Yes, safe isolation and IR testing require 10 tests rather than 3, but the principles are all the same.

The fuseboard thing is interesting. As things stand, TPN boards are bulkier and more expensive than SPN ones. As Zoomup suggests, you could have 3 SPN boards, but IMHO that is silly.

If a property has a TPN supply, will it use them? Range cookers can, EVCPs can. Lightbulbs cannot.

Many years ago when NSH were being promoted or where gas was not available 3 phase was often installed. Where I currently live there is a 3 phase 100A supply due to no gas being available in 1969 when it was built. The builder installed oil boiler so it's never been used. When we move here in 2016 I did consider electric heating instead of the oil but as gas came to the village in the 1980s but the previous owner was to mean to share the cost with next door to have a gas supply installed in one trench for the two properties. I bit the bullet, had gas and new central heating installed.

So we continued to use the blue phase but did replace the old MEM 6w metal single phase board for a standard 12Way with MCBs and RCD. The OP did not mention any 3 phase requirements so as Chris says just a bog standard domestic system is seguired and the DNO will use just one phase.

Not silly Chris, to have two or three single phase boards if no three phase equipment is to be run, and one phase is just not sufficient for the installations in question. As Norm above says one phase could just be for night storage heaters or off peak water heating. The other phase(s) for normal domestic use.

Z.

Longer term of course once there is a 3 phase supply in most houses it is likely that someone will want to use all 3 phases for something at some point, if only to fit 3 times as many not quite pre-notifiable solar panels, as the limit is 16a per phase, or a maybe larger car charger, where some 22kW ones are just the same current rating as the 7kW ones internally but with a contactor with a couple more poles. Then there are larger cookers that are easier to fit with 3 phases of 2,5mm2 rather than  6mm2 and a bent tin link that is clearly an afterthought for the UK export model. Mind you cooker isolators would need to catch up.
I think it is not a bad thing, 
Personally I'd suggest a 3 phase box with single pole breakers in most of the ways is perfectly sensible, if not common in domestic right now.  No need to have many rows of breakers.

An example





-only one true  3 phase load with 3 pole linked breaker, the rest are single phase MCBs that could just as easily have been RCBOs /AFDs if you must. (I may have preferred to see sleeves on unused bus pins, but that is not the main point to make .)

Some folks  assumptions about colours for 3 phase colour SWA re-used for single phase may need more careful checking before termination. black is not always the earth ;-) But as above, other places have been doing it for years without blinking, and I am sure we can join them.

Mike.

In the absence of any good reason to do otherwise, I would go for a three phase board rather than for 3 single phase units.

Firstly it will facilitate the use of three phase loads such as 22 kw EV chargers, 3 phase heat pumps, and perhaps large cookers. 3 phase is in my view the war forward for all but the very smallest new homes.