4mm Radial and re-wire Dillema

[Mattsparks]

Hi All nothing to do with this thread, but id like to start a new one any ideas how? I havent been on here for a while!

 

[Rpa07]

Click on Forums and you’ll see an orange ‘Post New Thread’ button. Away you go! @Mattsparks

 

[Midwest]

Select a particular category as well.

 

[sham]

Yes, 2.5 with 20 mcb is fine. I do most my house rewires in radial, one for the kitchen, one for down stairs and another for upstairs. We are using less power now in the energy saving world. Not all of the 11 sockets will be used at the same time continuously. You could have 50 sockets and end up using 2. Rcbo seem more practical as with a split load it will turn off more circuits.

 

[sham]

And Strima has a good point.

 

[Ian1981]

20 amp is tight for a kitchen in my opinion depending on what’s in it say a couple of sockets above worktop for toaster, kettle then you’ve got washer, dishwasher, dryer (constantly on in my gaff) so 20 amp I think is too low.

 

[Cadgey123]

I would be putting a 32amp supply to any kitchen. Too many larger appliances, ie toaster, kettle, DW etc etc

 

[Cadgey123]

I would be putting a 32amp supply to any kitchen. Too many larger appliances, ie toaster, kettle, DW as Ian said above

 

[Judd]

If you don't want to work with 4mm but want 32a why not wire a good old fashioned ring in 2.5mm? Seems like an obvious solution.

 

[Risteard]

Testing is the only way to be certain.

I can't completely agree with that statement. There is a reason inspection comes first in the phrase inspection and testing - it's because it is inherently far more important than testing. Testing merely supplements the inspection. So just because test equipment does not show any issue with cables (much of which is probably concealed in containment or the building fabric or buried or whatever) does not mean that they are necessarily in a safe condition.

 

[Ian1981]

Peoples thoughts about installing 4mm radial socket circuits in trunking?
For instance enclosed when entering the consumer unit say in a garage or cupboard area?
I’m thinking ccc of cable being perhaps only 30amp.

 

[Strima]

I can't completely agree with that statement. There is a reason inspection comes first in the phrase inspection and testing - it's because it is inherently far more important than testing. Testing merely supplements the inspection. So just because test equipment does not show any issue with cables (much of which is probably concealed in containment or the building fabric or buried or whatever) does not mean that they are necessarily in a safe condition.

I have to agree, I just missed 'inspection' out of my sentence.

 

[Wilko]

Peoples thoughts about installing 4mm radial socket circuits in trunking?
For instance enclosed when entering the consumer unit say in a garage or cupboard area?
I’m thinking ccc of cable being perhaps only 30amp.

Agree, I don't do it.

 

[davesparks]

The colour code of the house is red and black flat twin and earth.

I’m not 100% brushed up on part p regs or even 17th edition as it’s not a required qual in my area of work.

The colours of the cores in the cables are irrelevant to their suitability for continued use.

If you don’t have a good working knowledge of part P and the current wiring regulations then how can you claim to be competent to carry out the work?
Without knowledge of the regulations how can you comply with them? And if you don’t comply with the regulations how can you be competent?

 

[Sylvia Namusisi]

Hi new to the forum and thanks for any help,

Parents have bought a typical 1930s 3 bed semi which had a rewire in the early 70s. I’m guessing the consumer unit has been updated since then because all circuits are protected with RCBO’s ( 2 x 6amp lighting circuits 1.5mm cable, 2 x 16amp radial socket circuits 2.5mm cable, 4 x 32 amp radial socket circuits 4mm cable)

I’m considering doing a re wire to update the cables and sockets also need adding to circuits etc, however I’ve hit a bit of a dilemma. I was considering upgrading the 16amp RCBOs to 20amp using 2.5mm cable, is that ok?

Also because I really seem to struggle a bit with 4mm cable ( room in back boxes, 2 cables in oval conduit issue, fitting 2 cores easily in sockets terminals etc) I was thinking of downgrading the 32 amp breakers to 20 amp and using 2.5mm cable radial circuit. However I’m unsure if 20 amp is enough. One circuit would be upstairs sockets (approx 11 double sockets) and the other circuit would be downstairs living rooms and hallway (approx 11 double sockets also) these sockets will only have the usual appliance plugged into them with the occasional use of an iron/hairdryer/straiteners being the highest power. Would 20amp be enough or am I best just dealing with the 4mm cable and 32amp RCBOs to prevent any worry of overload.

Also if I was to change the 4 RCBO’s that would cost in the region of £120-160. Would I just be best buying a split board RCD consumer unit and just using ring circuits for sockets or would you recommend paying the extra for the RCBO’s and use radial circuits?

Hope this all makes sense and sorry for it being long winded. Appreciate any feedback and help!

Hi sorry to be stingy but you talk about changing protective devices and cables as if you just change them as you want.
Have you actually done cable calculation to find out yr maximum load ,things like Ib,In etc to enable you to choose a correct protective device? ?