Rcd & mcb ratings

[steq184]

Hi
I’ve just built myself a home bar to the side of my house.
Just need to run electrics now.
Am going for a 2 way consumer unit. One circuit for lights and one for sockets.
Lighting circuit will have 4 wall lights and probably a few more over the bar (not made my mind up yet)
Curcuit for sockets will have;
Fridge
Tv
Juke box
Fruit machine
Transformer for bar pump lights.
Convector heater.

What size RCD and MCBs would I ideally need to have fitted?

Thankyou in advance for your help

 

[ericmark]

You need to design, as you will sign the installation certificate saying you have designed it. For lighting very little load so likely standard 6 amp overload, for the rest likely 16 amp is enough, we tend to have standard sizes, 13A for a fused spur, 16 or 20 amp for a radial and 32 amp for a ring final.

But the power does not come out of the air, you will likely have a large overload in the orignal consumer unit supplying the sub main, you also need to work out volt drop and decide how to bring that power in, SWA and a non RCD protected supply, or other methods, and ditance is important.

I was required to submit a detailed plan in 2004 when I wired a wet room, then I had to submit my installation certificate to get the completion certificate, I also had to show I had the skill to do the work.

My convector heater uses around 50W of electric power, plus of course the power from the hot water pipes of the central heating, however I have seen 9 kW convector heaters, we have no idea of size of room, distance from consumer unit, or how much power is required. We also should have the prospective short circuit current or earth loop impedance readings before we could even start a design, also know the supply to the house. All we can do is guess, and guess is not good enough.

 

[winston1]

Is it actually on the side of the house or completely detached?
I'm thinking you don't need a separate CU at all. Just extend the existing lighting and ring final.

 

[steq184]

It’s attached to the house. Was going to extend from the house but want a consumer unit so I can turn total power to the home bar.

Cheers

 

[ericmark]

Depending on relationship with main consumer unit i.e. how close to centre of the ring final, it is possible to have a switched fused connection unit and be able to switch a 13 amp supply on/off without the need for a consumer unit. Using again a switched FCU with 3A fuse for lights the lights can be fed from the ring final.

However you need to plan not simply throw it together.

So heating first, if you want to be able to leave the room unheated except when occupied, then you need some thing able to pump out a lot of heat when required, using a Myson fan assisted radiator would likely be best option, with outputs up to 5 kW much higher than any direct electric model and cheaper to run, with the ivector it has variable speed fan so will regulate the heat in the room independent to rest of house as long as boiler is running. However with total electric the heater may cost less to buy but also cost more to run and installation cost to get a large supply may end up as expensive as hydronic types.

Once you have decided how to heat, you should be able to work out electric load, relays and supplies of up to 3 kW can be easy controlled by remote controls, over that magic 3 kW the cost goes up by a huge amount, so you really do need to decide if under or over a 3 kW load (13A) also coolers do not like volt drop, and I fail to see how items like coolers can be switched on/off as required, in the main beer takes a long time to cool, so coolers left on 24/7. 12°C is the normal temperature of a wine fridge, and beer tends to be the same, I know to cool 40 pints of home brew in a freezer using 60 watts from 24°C to 19°C takes around 2 hours with the motor running for around 1 hour of that time. So down to drinking temperature looking at around 6 hours for a full fridge with 40 pints. So can't see how you could simply switch on as required? And real ale does not like being heated and cooled.

From what you have said so far it would seem you still have a lot of planning. And beer can freeze, so you would need some power 24/7 even if some is only switched on when required.

 

[Taylortwocities]

As Eric has said. What you are contemplating is notifiable work. It is new circuits and a new consumer unit.
If you plan to do it yourself, you need to first raise the case with the local authority's buildiong control (and pay their fee).

Then you'll need to design install, test and certify the circuits in accordance with BS7671 and demonstrate that you have done that to the local authority (who will want to inspect a various stages). You aren't going to be able to do this by asking basic and spurious questions on an Internet forum. Sorry.

The alternative is to have an electrician who is a member of one of the Competent Person Schemes do the work for you.

 

[ban-all-sheds]

It’s attached to the house.

So you must have applied for Building Regulations approval.

What did you say, or by default allow Building Control to assume, would be the way you would comply with Part P? Because if they are expecting one thing, and you then go and do something different, you might find that they refuse to give you the completion certificate. If you made no mention of it, check their website - there is a very good chance that you are expected to have all the electrics done by a registered electrician.