Running radial spur from defunct cooker circuit

[bozzle]

Hi,
I am planning to run a radial circuit from a defunct 6mm cooker circuit. As I will attach a 2kw oven and a 2 kw washer as well as other smaller kitchen appliances I assume I will need a 32 amp fuse.

I was planning to run 2 separate spurs from 6mm in 2.5mm cable for washer/oven to ensure cable load not exceeded but do I need to use 4mm cable if I am using a 32amp MCB?

Will used a registered electrician to do the work but it impacts on how I do other work /obtain quotes

Any advice would be much appreciated.

 

[EFLImpudence]

Hi,
I am planning to run a radial circuit from a defunct 6mm cooker circuit. As I will attach a 2kw oven and a 2 kw washer as well as other smaller kitchen appliances I assume I will need a 32 amp fuse.

Just as well. Is it not there already.

I was planning to run 2 separate spurs from 6mm in 2.5mm cable for washer/oven to ensure cable load not exceeded but do I need to use 4mm cable if I am using a 32amp MCB?

Yes, 4mm² or use 20A mcb.

 

[bozzle]

Thanks for the prompt response. Presume it would be OK to run separate spurs in 4mm from junction boxes for each double socket to avoid trying to get two 4mm cables in a double socket which I think could be tricky

 

[EFLImpudence]

Yes.

Junction boxes must remain accessible for testing.
Where will it be?

 

[bozzle]

Junction boxes would be underneath kitchen base units and accessible if plinth lifted off.

 

[bozzle]

Presume simplest solution would be to use standard cooker switch with socket and run oven from socket(OK according to maker) and then run down wall in 4mm to 13a fused spur under base u nit and behind plinth after which I could use 2.5mm

 

[EFLImpudence]

Ok. Use modern ones with cable restraints.

https://www.wagobox.com/
There are other brands.

You will, obviously, require those that can take 6mm² conductors.

 

[EFLImpudence]

Just noticed this one.

Presume simplest solution would be to use standard cooker switch with socket and run oven from socket(OK according to maker) and then run down wall in 4mm to 13a fused spur under base u nit and behind plinth after which I could use 2.5mm

Yes, but a bit (lot) naff having the flex showing.

If you still have the cooker connector behind the oven you can just use that for both with 4mm².

 

[EFLImpudence]

Don't forget to label the consumer unit appropriately.

 

[bozzle]

Now I have an idea how the job should be done I can get get a couple of quotes

Many thanks

 

[ban-all-sheds]

You know this:

Hi,
I am planning to run a radial circuit from a defunct 6mm cooker circuit. As I will attach a 2kw oven and a 2 kw washer as well as other smaller kitchen appliances I assume I will need a 32 amp fuse.

I was planning to run 2 separate spurs from 6mm in 2.5mm cable for washer/oven to ensure cable load not exceeded but do I need to use 4mm cable if I am using a 32amp MCB?

and all your other questions and assumptions you've wanted confirmed really do not tie in with using an electrician.

Will used a registered electrician to do the work

But not one who you trust to select the right cable size, MCB rating, use appropriate accessories and installation techniques, eh?

but it impacts on how I do other work /obtain quotes

How so?

Now I have an idea how the job should be done I can get get a couple of quotes

Can you?

How, when you haven't yet asked us what to tell him about complying with the regulations for RCD protection, concealed cables, earthing and bonding etc, nor about what tests to tell him to carry out, what sequence to do them in and at what point he should energise the circuit, and for each test to tell him what is being measured, why it is important, how to carry out the test, and with what equipment, and what sort of results to expect to get if everything was OK?

 

[ericmark]

There are many ways to use an old cooker supply to feed multi-outputs.
To keep the 32A supply either cable able to take that current or reducing the maxium output for each circuit is required.

From forming a ring to installing a mini consumer unit or even using a grid swich with multi-fuses or using cable able to take the full load are all options.

This is called design and the person doing this will need to sign that they have the ablity to do this design work.

One of the major problems when extending old circuits with new bits is the new bits have to conform with new regulations and that includes to buried in wall at less than 50mm rules and RCD on nearly all sockets rules.

The design is selected with RCD use in mind and since you don't stipulate if RCD already fitted or not I can't really say what would be the best option. There are RCD FCU and RCD sockets but also one has to then consider the volt drop under fault conditions.

Again part of the design you need to know the loop impedance figures to decide if active or passive RCD's are used. Using active may be electricialy safe but this does mean after a power cut they need resetting which for fridge or freezer is not what is wanted.

The next signiture required is for the installation. One would assume following the design but again you sign to say you have the ablity.

Finally there is the inspection and testing here you take all the readings and enter them into the paperwork to show that the impedance and insulation are within the regulations and that cables are protected again as reguired by the regulations.

OK I know many DIY guys don't follow the regulations but you say your going to hire an electrician who clearly will so unless you have the ablity to design then you really do need to leave it to the electrician to do all three tasks.