3 phase to Single phase

[greg12345]

We need to create three single phase circuits, one 16A for a machine, one 6A for some lighting in the area. Maybe another 16A/32A circuits for some sockets.

We already have 4mm 4 core SWA cable running to the area (surface mounted) its a 3 phase supply protected by a 32A cicuit breaker.

What would be the best way to use this feed? Could we potentially buy a small consumer unit and have each phase supplying each new circuit?

We will be getting an electrician to carry out the work, but ideally want to buy materials ourselves.

Many thanks

 

[ban-all-sheds]

This is actually quite simple.

Let the electrician take complete responsibility for the design (he has to), and let him supply the materials (he can get them cheaper than you).

 

[greg12345]

Ok fair enough ban-all-sheds, I just wanted to know really if I had to buy more SWA as I know that buying 20 meters is expensive, never mind

 

[ban-all-sheds]

Only your electrician can say whether SWA will be needed once he has done a site survey and assessed the environmental factors.

And 20m of cable is not expensive.

 

[greg12345]

Ok I will leave it to the sparky, what have you got against sheds by the way?

 

[ban-all-sheds]

not

 

[greg12345]

Sorry you've lost me

 

[ericmark]

The likes of B&Q are called sheds. They sell all sorts of products without any regard to if they could be legally used by the general public.

In this country very few items have restrictions as far and buying and selling. Guns do but Gas boilers, Radio transmitters, and many more items can be sold to general public but not used by the general public.

Be it a wood burner or a simple socket there are restrictions on how they can be fitted and the sheds do not seem to care about telling you about the safety problems when used without the correct infrastructure.

For example to fit a replacement socket then it only needs testing but to fit a new socket you must also ensure RCD protection.

Personally I am not so worried about that but it's the lack of spares which I find is a problem. You can buy a whole shower but lose a simple washer and you can't get a replacement.

As to your question single phase from three phase where a neutral exists normally not a problem. But where there is no neutral then it can required transformers. Even where there is a neutral one has to look at the current the neutral will carry and so not really a DIY job.

In the main 3 phase means commercial and as such the blame culture is to be considered. I have been a qualified electrician for many years but on one job I was given the title of charge hand mechanic and although I had worked for the same firm both before and after as an electrician because my title was mechanic I was not allowed to work on low voltage without a person who's title was electrician being with me. Even though he had not a clue about what I was doing in theroy he was in charge. It was all down to insurance.

 

[greg12345]

Cheers ericmark, I'm with you now

Down with sheds!