Fuse allocation recommendations for CU in a bungalow

[Forsh]

I'm about to start a full bare brick refurb on a bungalow and was looking at my options to use the 10 ways in a split CU

Layout will be lounge and kitchen at the rear, two beds and bathroom at the front with a fire door splitting front and rear

Should I split ring main and lighting circuits either side of fire door?
should I have the kitchen separate form the lounge? or fridge freezer separate
attic
smokes
outside lights?

a given:
shower
cooker

What's best - simple or complex ? pros cons?

 

[ban-all-sheds]

I'm about to start a full bare brick refurb on a bungalow and was looking at my options to use the 10 ways in a split CU

A bit AAF, surely? Why not base the design on what you need, and pick a CU accordingly?

Should I split ring main and lighting circuits either side of fire door?

It's up to you. How do you know that a ring final is the most appropriate choice anyway?

should I have the kitchen separate form the lounge?

It's up to you.

or fridge freezer separate

It's up to you.

attic
smokes
outside lights?

It's up to you. Do you want outside lights?

What's best - simple or complex ?

As simple as you can have it to give you the functionality you need, avoiding unnecessary complexity is a pretty good plan.

pros cons?

All sorts, but only you can say what matters to you.

What are you planning to do about Building Regulations approval for the electrical design and installation? How do you propose to comply with Part P? It is highly likely that your electrician will have to be the one to make all these design decisions, or at least be the one to answer your questions, discuss the pros & cons, and then do the design to your requirements.

 

[flameport]

Such a question probably has hundreds of answers, there is no single correct choice.

From what you have suggested:
Split CUs, as in those with 2 RCDs, are a poor choice.
10 ways seems rather oversized for a 2 bed bungalow.
Why an electric shower? They are hopeless and only used when there really is no other option. For a 'full bare brick refurb' pretty much every choice of shower and water heating would be available.
There is no reason for a separate circuit for a freezer. If going along that route, may as well have a separate circuit for every socket in the house.

 

[Risteard]

There is no reason for a separate circuit for a freezer.

That's hardly true so long as you wire the circuit so as not to require RCD protection, or protect it with a dedicated RCD (whether that be an RCCB only protecting that circuit in concert with a circuit breaker/fuse, or an RCBO). Then there is very good reason for doing it.

 

[stillp]

My response to the title of the thread would be to not use fuses, use MCBs instead!

 

[Forsh]

Thanks for the replies guys
Just trying to maximise my knowledge before I speak to a spark so I'll have an idea if he BSing me or being fair
and to get an idea of what's feasible and what should be avoided. Of coarse he knows better than me what's required as a minimum but if I don't ask for extras now then I probably will just get what's easiest for him

10 way CUs are always the ones on offer and if i don't use all the ways then so be it but if I have them...

re shower: had a shower once run off a combi and had to throttle the flow back in winter to get it to run warm enough but it was a large overhead shower head so maybe a more standard type shower head off a combi is more suited - I'll give that some thought

re freezer: I'm thinking if I do the kitchen ring separate I wont do freezer but if the kitchen is combined with other rooms then separate but not RCD protected

Stillp - have you got nothing better to do?

 

[stillp]

Stillp - have you got nothing better to do?

Nope!

 

[flameport]

re shower: had a shower once run off a combi and had to throttle the flow back in winter to get it to run warm enough

Same applies to an electric shower, but the effect with the electric one is far worse.
Most powerful electric shower you can actually fit in a house is typically 10.5kW.
Most combi boilers are around 3x as powerful, in the 30kW range.
If you want a large high flow shower head, then a proper hot water system is required.

re freezer: I'm thinking if I do the kitchen ring separate I wont do freezer but if the kitchen is combined with other rooms then separate but not RCD protected

Why would you (or anyone else) not want RCD protection for a fridge or freezer?

 

[Forsh]

Why would you (or anyone else) not want RCD protection for a fridge or freezer?

I can see the argument both ways

Ultimately I suspect the freeze will be on the dedicated kitchen ring and RCDed (It's not going to the biggest of fridge/freezers in a 2 bed anyway so not a lot lost in case of a trip for the sake of better protection)

 

[EFLImpudence]

It's circuits - for personal protection - that have to have RCD (or other) protection; not appliances.

Why would you want RCD protection for a freezer?

 

[deadshort]

It's circuits for - personal protection - that have to have RCD (or other) protection; not appliances.

Why would you want RCD protection for a freezer?

Beko, for starters !

DS

 

[Forsh]

Should any consideration be given at this stage to electric under-tile heating in the kitchen and bathroom or just fused spare off the relevant ring main (hall in the bathroom case)

 

[stillp]

Personally, I wouldn't waste time and money on UFH, which I've found to be unreliable and difficult to control. Other opinions are available...

 

[flameport]

In a properly designed and installed installation, RCD tripping occurs when something is defective. This is a rare event. Somewhere between once a year and never.

If the freezer causes the RCD to trip, then the freezer is faulty and food is destroyed. Whether it has a separate circuit or not makes no difference.
If the freezer circuit has no RCD, some faults which would have caused the RCD to trip will go unnoticed. This could be the freezer causing a fire and destroying your house as well as the food contained inside.

On a shared circuit where some other item causes the RCD to trip, then it is likely to be noticed fairly quickly, as the rest of the kitchen won't have power. Usual culprits being kettles, toasters and irons, all of which would be noticed immediately or within a few minutes. Washing machine or dishwasher perhaps an hour or two later.

If the washing machine or other appliance causing the fault was switched on, then everyone left the house for the day, the fault would not be detected until hours later. However a freezer or fridge does not instantly defrost once the power has been removed, a suitably low temperature can be maintained for many hours if the door is kept closed.

If some fault occurs when the house is unoccupied due to holiday or similar, the fault may not be noticed for days or weeks. Food destroyed.
However who in their right mind would stuff the freezer full of expensive food and then go on holiday for a month?

 

[JohnW2]

Beko, for starters !

It's a little ironic that when Argos brand, and sell, Beko products as 'Bush' ones, many/most people then think they are buying UK-manufactured products from a highly reputable and long-standing UK company!

Kind Regards, John