Kitchen wiring - please tell me if I'm wrong....

[martom]

Hi, I need your advice again

I have a flat to do: Old CU, old wires colour, kitchen radial 4mm

To do - rewire kitchen, new CU

I checked the installation, will not trip the RCD

Now the question - I would like for my peace of mind run new cable from CU for the kitchen circuit, but the kitchen is ca 15m away from CU, newly redecorated corridor, lounge ets.

Q1) Is it OK to crimp new 4mm to the old one and just rewire the kitchen?

Q2) One of the bedroom sockets is powered by a kitchen circuit. Is it al-right by regulation?
Thanks
Tom

 

[Adam]

Q1: As long as the joint is suitably enclosed, yes.

Q2: The are no regulations that prevent the bedroom socket from being on with kitchen.

Assuming the 4mm2 radial does not cover a large area, there is no reason why this can not be done and put on a 32A mcb as per regs.

 

[kingeri]

Just watch installation method if using 32a breaker with a 4mm2 radial. Even running in trunking or conduit brings it down to 30a CCC, hence requiring a 20 or 25a breaker. Only installation method C will allow you to use a 32a breaker......and that's not even factoring in derating factors like grouping, etc. If it were me, and I had the opportunity to put things right, I'd install a 100% brand new 2.5mm2 ring for the kitchen, and if possible kick that bedroom socket into touch.

 

[Darkwood]

Q1 the crimping of cables has to be done correctly, you haven't suggested how this will be done - enclosed in jointing box or are you expecting to bury them, if the later and i would assume from asking the question you dont possess the required heat gun and heat shrink insulation sleeving + outer environment sleeving with moisture barrier to perform this task correctly.
If you could give more info as to how you intend to extend the cables with more info than just saying crimping we could advice accordingly.

I dont understand why the corridors and lounge been re-decorated would be an issue as you would normally run them under the floor boards on the ground floor or through the boards on the first floor or are you saying this isnt an option.

 

[Adam]

I dont understand why the corridors and lounge been re-decorated would be an issue as you would normally run them under the floor boards on the ground floor or through the boards on the first floor or are you saying this isnt an option.

OP states it is a flat. Most likely concrete floors.

 

[martom]

I was thinking of properly crimped wires buried into the wall. I use heat shrinking isolation separately on each wire (does not matter to me that the connectors are isolated) and finally the whole cable goes into heat shrinking isolation again. I use electric heat gun for this... and ratchet tool.
I would like to go back with 2.5 mm, but its a large flat in block, concrete floor with wooden oak floor on it, walls and ceilings re-plastered and redecorated.

The installation method C - cable in masonry wall with no isolation- no trunking, no conduit

Thanks for all your advice
I love this forum

 

[Darkwood]

You need to learn to spell Insulation as it will confuse many as isolation as you know is also a well used electrical term,-- yes! get the drift now with the concrete floor ceiling but worth questioning as many flats exist in converted buildings and are not of concrete slab structure.
Regards the kitchen rewire, alot depends on size of kitchen etc and whats in it as to the practicality of re-using the 4mm, a seperate ring would be better and maybe utilise the 4mm to have the fridge freezer on an rcbo to keep it from been prone to defrosting if unrelated fault trips one of the rcd's covering it.

Customers preferences should always be taken into account but be careful the cart dosn't lead the horse, if a owner/tenant or council decides to have this work done after the nicely decorated hall has been done then thats not your problem and if the design of the installation would be better if a new ring was installed then this should be you approach to expressing the owner/tenant the need to upset her decor'.

 

[DNS1]

Q1 the crimping of cables has to be done correctly, you haven't suggested how this will be done - enclosed in jointing box or are you expecting to bury them, if the later and i would assume from asking the question you dont possess the required heat gun and heat shrink insulation sleeving + outer environment sleeving with moisture barrier to perform this task correctly.

I was always taught that self-amalgamating tape was always an acceptable option... Certainly easier to use than shrink...

 

[martom]

Hi - apart from 4mm I have in the near - just behind a wall 10mm power shower cable which will be unused now. Is there a way to use this cable for the kitchen? I just don't have any idea how?
There is no more electric power shower installed -just wires stayed.

Thanks for pointing me the spell difference between isolation and insulation I will remember now.

 

[Darkwood]

This method is old and crude IMHO ... the actual crimps should be sleeved with an insulating sleeving as even insulated crimps are open ended, then the sleeved crimped cores require a overall sleeving that gives the inner sleeving environmental protection and always good to ensure the outer sleeving comes with moisture barrier.
Yes amalgamating tape may acheive both insulation and environmental barrier but becomes bulky if wrapped correctly, where as the heat shrink can give a joint or similar thickness to original cable and is easy quick and provides the insulation barrier between cores that i would assume is required, i see alot of issues trying to stretch amal' tape around individual cores then a final over-wrap. We have better methods noow especially when burying it in plaster i would always go with heat shrink.

 

[Octopus]

I checked the installation, will not trip the RCD

Why doesn't the RCD trip??

 

[martom]

There is no rcd now, i mean the rcd will not trip unnecessary will operate correctly.

 

[Octopus]

There is no rcd now, i mean the rcd will not trip unnecessary will operate correctly.

If you are chasing in cables you'll need to instal rcd.s too. Bonding?

- - - Updated - - -

There is no rcd now, i mean the rcd will not trip unnecessary will operate correctly.

If you are chasing in cables you'll need to instal rcd.s too. Bonding?

 

[martom]

Yeah thats why the consumer unit will be changed - the whole flat will run on rcd now

 

[SYKRAPS]

Why doesn't the RCD trip??

I think that the OP is saying that he has performed dead tests and that if an RCD is installed there will be no nuisence tripping with regards to the already installed 4mm cable