Domestic rewire radials or ring final,s ???

[tuckermot]

Hi all

normaly on my rewires i do ring finals but on the rewire i am about to start in april ( 3 bed semi ) i was considering using radials for the sockets using 4mm t&e and 32a mcb just want to know is any one eles out there rewireing domestic properts using radials or sticking to ring fianals ??

Richard

 

[jase]

Those that keep going on about the ease of installing Radials over rings and why they use them, are just telling me they have trouble testing and fault finding.


How can it be any easier to install a radial??? there are still 2 cables going in and out of every socket unless its the last one!!!, as for having trouble testing, i have no trouble testing a ring, but find it less time consuming testing radials which is why i like to use them when ever i feel the need, last re-wire i did was a 2 up 2 down terraced house, upstairs radial, downstairs radial, both on 20A, and kitchen ring.

Just done a kitchen re-wire in a 2 bed ground floor flat last week and wired in 4mm 32A radial

 

[Fin170]

On rewires I make better use of radials, mostly to deal with disturbance to occupied homes. Can clear out 1 or 2 bedrooms and put them on radials working by the end of the day then move onto other rooms the next.

Kitchen and other current hungry rooms will usually be rings where doable.

 

[Jimmyb]

you always use a 25a mcb on 2.5mm radial as long it under 25meters

 

[imago]

I always install radials, but sometimes I loop them back to the CU.

 

[rich.250]

As far as I read it ( this is from 17th edition 2008) unless its changed
4mm t/e 70c Reference Method A ccc = 25 amps
Reference Method B ccc = 30 amps
Reference Method C ccc = 36 amps
reference method D isn`t relevant to domestic

So if you do anything other than clipped direct over the whole cable run you cant use a 32 amp MCB anyway.

Will put on my tin hat and await the incoming fire!!!!

I agree, it is hard to achieve a 32a radial. And to be realistic it's hard to achieve a 20a in 2.5!! Unless it's clipped direct.

 

[GLENNSPARK]

you always use a 25a mcb on 2.5mm radial as long it under 25meters

and would you not consider the installation method??......

 

[rich.250]

and would you not consider the installation method??......

My point exactly....

 

[GLENNSPARK]

My point exactly....

yes....sorry rich....just noticed #35.....

 

[rich.250]

Lol. For 25a radial in a thermally insulated wall. Probably be looking towards 6mm lol. Without doing the calc

 

[GLENNSPARK]

4mm for a 25A radial....method A....

 

[rich.250]

True. I was more thinking surrounded by insulation.
4mm would suffice.

 

[TaffyDuck]

So all the guys who have been putting in 4mm T/E radials on B32s, what are you going to do about it?

Change the MCB for a 25 or pretend its in 90c thermo?