Switches above worktop for appliances below and cable question

[markymark2406]

So putting In a new kitchen, I’m running a new radial circuit from a 32amp RCBO at the DB in 4mm twin and earth, some appliances will be inbuilt and need to be fed from a fused spur above the worktops going down to a unswitched 13amp socket below the worktop.
My question is do I have to feed the socket below the worktop with 4mm twin and earth or
Is 2.5mm sufficient ?

 

[davelx]

2.5 is fine, its one of the configurations in the appendix of the regs, referred to as a spur off a radial. Overload protection is provided by the fused spur, fault protection by the OPD.

 

[sparkwright]

Yes you can use 2.5mm2.

EDITED to match up with Dave's very correct info.

 

[sparkwright]

2.5 is fine, its one of the configurations in the appendix of the regs, referred to as a spur off a radial. Overload protection is provided by the fused spur, fault protection by the OPD.

What fused spur?

 

[davelx]

the ones the OP mentions in the first post. Though he could just use a 20A DP switch if he wanted the convenience of above counter isolation, as the fuse in the plug will also provide overload protection.

 

[sparkwright]

the ones the OP mentions in the first post. Though he could just use a 20A DP switch if he wanted the convenience of above counter isolation, as the fuse in the plug will also provide overload protection.

Ah, so he has. I read that twice and didn't notice - too wrapped up in the other current topic about grid switches/20amp switches.

 

[EFLImpudence]

It does get confusing when fused spurs are run from fused spurs, doesn't it?

It's also good that the OP is installing an RFC instead of the usual RFC.

 

[SUNRAY]

It's also good that the OP is installing an RFC instead of the usual RFC.

 

[TimboTwo]

It's also good that the OP is installing an RFC instead of the usual RFC.

Not sure where you got that from, EFLI.

 

[SUNRAY]

True.
But in this instance, as the appliances are to be built in you would not be able to access the fuse in the plug as it will be behind the appliance. The way to do it is to have a fused connection unit above the worktop and a cable outlet behind the appliance, with the dishwasher, etc lead being hardwired to the cable outlet.

I do agree with the concept and happily accept either method as perfectly acceptable.
In my opinion this is one of the situations where our 13A plug system falls down. Going back to the 70's I did a fair bit of work for a builder and he spec'd 15A sockets on fused spurs for appliances.
I prefer to retain the plug for maintenance convenience etc. I'd err on caution and fit a FCU and 13A socket for future proofing and suffer the inconvenience of 2 13A fuses in circuit on the rare occurrence that one blows than requireing tools to remove a machine, especially as many appliance leads are now much shorter than they used to be.

 

[securespark]

Not sure where you got that from, EFLI.

He's quite right!
The OP plans to install an RFC instead of of an RFC.

Keep up, man!

 

[EFLImpudence]

Yes, the OP states it in the OP.