Rings or Radials ....

[Octopus]

Just started on a complete refurbishment / extension on a 3 bedroom property which is having a complete rewire.

I'm not keen on Dual RCD boards, nor trying to have as few circuits as possible ....

So when it comes to the socket circuits I was thinking of:

Radial 20A for hall, lounge and dining room
Ring 32A for kitchen
Radial 20A for upstairs

Anyone like to comment?


PS the plumber was asking me today why I was installing 35 mm boxes - he seemed to think 25 were always best!

 

[Pete999]

Just started on a complete refurbishment / extension on a 3 bedroom property which is having a complete rewire.

I'm not keen on Dual RCD boards, nor trying to have as few circuits as possible ....

So when it comes to the socket circuits I was thinking of:

Radial 20A for hall, lounge and dining room
Ring 32A for kitchen
Radial 20A for upstairs

Anyone like to comment?


PS the plumber was asking me today why I was installing 35 mm boxes - he seemed to think 25 were always best!

If you don't like dual RCD boards do you intend using RCBOs? I would imagine it's your choice what size back boxes you use, why is the Plumber sticking his oar in? sometimes the deeper the back box the better. Maybe in questioning your choice of back boxes, he was gleaning information from you, ask him why he is using the size of pipe he has chosen, just for a laugh.

 

[Spoon]

If they have the money then put one radial per bedroom, then when any of the kids wont come off the PS4 or Xbox you can just flip the switch to that room..

 

[Ian1981]

Why not a 32 amp radial for the kitchen using 4mm cable then you won’t have any rings?
Depends as well if your using 2.5mm for a 20amp radial that you don’t exceed the maximum zs for the mcb which will be 2.19 ohms for a type B that is 1.75 ohms with rule of thumb and if it’s larger that the recommendations in appendix 15 you may have volt drop issues.
Perhaps 4mm radials for all 3 if you don’t want to install ring finals on 32 amp mcbs reference method permitting.

Ps I only ever use 35mm with things like fused spurs or if I’m fitting flat plate sockets.
It’s true that you’ll probably have more flexibility with 35mm but they you go.
Try asking my gaffer to start fitting bigger than 25mm boxes for sockets on new builds I know what the answer is............

 

[ipf]

Rings......when it suits.
Radials ......when it suits.
So I can't see any problem with your plans.

I, generally, can't see any problem with 25's. You can always sink them in a bit further, after all.

 

[suffolkspark]

if your doing a 20a radial upstairs you'll probably have to wire it in the floor and not the loft (ref method 101 may be an issue)

 

[Octopus]

If you don't like dual RCD boards do you intend using RCBOs?

I stopped fitting dual RCD boards when the AMD3 rules came along - RCBO boards everytime since then.

 

[sam400]

Don't install ring finals myself. Always 35mm boxes though

 

[7029 dave]

IMO, if you are rewiring RFC always, as for the split board, up to you if the client will spend the money RCBO's, I like that option anyway. 35mm boxes more bashing so what.

 

[willy fixit]

Always check what style accessories they're thinking of then there no surprise when they want flat plate shiny outlets squeezed into the 25mm boxes - Thank goodness for spacers and a big black permanent marker!

 

[Pete999]

I stopped fitting dual RCD boards when the AMD3 rules came along - RCBO boards everytime since then.

Thanks

 

[Des 56]

I have a very vague memory of using 25 mm boxes
The memory seems to coincide with some numpty coming up with the idea of making flat plate accessories

The scary part is that there were customers who actually liked the monstrosities,it made me realise they were here to stay and the days of the good old 25mm box were history

 

[Ian1981]

I have a very vague memory of using 25 mm boxes
The memory seems to coincide with some numpty coming up with the idea of making flat plate accessories

The scary part is that there were customers who actually liked the monstrosities,it made me realise they were here to stay and the days of the good old 25mm box were history

I believe it was satin himself

 

[Midwest]

I stopped fitting dual RCD boards when the AMD3 rules came along - RCBO boards everytime since then.

I've fitted a few RCBO only, but MK only, errkk!. The rest are somewhat more expensive, unless the client doesn't mind paying more?

 

[Leesparkykent]

35mm as standard here and 47mm for media plates. 25mm on cheap white plastic, rental rewires.

 

[Leesparkykent]

I've fitted a few RCBO only, but MK only, errkk!. The rest are somewhat more expensive, unless the client doesn't mind paying more?

I can get a 10way lewden/control gear board with 8 RCBO's for £99

 

[Octopus]

I fit the Control Gear units - as Lee says - a small premium, for a simpler set up and far easier to fault find when it starts tripping.

 

[Andy78]

I have used the lewden boards too. Seem fine to me.

 

[Toneyz]

I stopped fitting dual RCD boards when the AMD3 rules came along - RCBO boards everytime since then.[
Deleted

 

[Dozer 73]

Only problem with 35mm boxes , not so good on the single skin walls , very easy end up in next room

 

[123]

Only problem with 35mm boxes , not so good on the single skin walls , very easy end up in next room

Are you chasing the walls with a jack hammer or something?

 

[Dozer 73]

Are you chasing the walls with a jack hammer or something?

Of course , why what do you use
Residents aren’t usually too happy with a compressor in their living room though

 

[123]

I fit the Control Gear units - as Lee says - a small premium, for a simpler set up and far easier to fault find when it starts tripping.

What do you fit if it's TT?

 

[123]

Of course , why what do you use
Residents aren’t usually too happy with a compressor in their living room though

Wall Chaser and SDS Chipping Hammer - have yet to burst into the next room with 35mm deep boxes

 

[Dozer 73]

Can’t say I’m an expert on the house bashin so I,ll stand corrected
And probably leave it to the specialists

 

[Octopus]

What do you fit if it's TT?

not had one yet but I'm thinking 100 mA RCD in place of the 100a dp switch

 

[Leesparkykent]

not had one yet but I'm thinking 100 mA RCD in place of the 100a dp switch

Wouldn't be a good idea with them control gear RCBO's due to not being double pole or SPSN. The new wylex compact RCBO's are SPSN I believe.

 

[Ian1981]

deleted

 

[westward10]

Wouldn't be a good idea with them control gear RCBO's due to not being double pole or SPSN. The new wylex compact RCBO's are SPSN I believe.

Does that matter if they are only being used for circuit protection and not isolation with the main double-pole rcd supporting them.

 

[Leesparkykent]

Does that matter if they are only being used for circuit protection and not isolation with the main double-pole rcd supporting them.

well yeah unless you want the whole board tripping in the event of a neutral-earth fault...RCBO trips, as it's solid neutral the neutral isnt disconnected so takes out the upfront time delayed RCD.