Feeding a Sub Main

[aj2304]

Hi all,
im a recently qualified electrician who is looking for a bit of advice. A friend of mine (also an electrician) has asked for my help on one of his jobs. The job is feeding a sub main distribution board which is located in the porch area. It is only feeding two circuits, one being a 32a small ring circuit in the shed in the garden, and the other being a 6a lighting circuit feeding the light in the porch. The problem I'm having is that my friend is wanting to feed the board using a 10mm PVC twin running it under the flooring from the main fuse board. He's saying that he thinks it's fine running it straight from board to board. However I'm sure that along the lines somewhere you have to run it through a spur? The run is only around 10-15 metres from board to board but I just wanted to check before my name would be going on the test sheet. Sorry if this is a dumb question however I don't do much domestic work in my job.
thanks for any help.

 

[Marvo]

I'd strongly suggest you shouldn't sign off work that you haven't done.

How is the shed ring final going to run from the porch?

Why would you need a 10mm twin cable to supply a shed socket or two and a porch light unless there a massive distance involved?

 

[Engineer54]

Something not quite right here!! A couple of questions, ...why is this CU that is supplying a garage FRC located in the house porch and not in the shed?? How are you intending to wire this shed FRC from the porch CU?? Why can't the porch light be fed from the existing lighting circuit??

 

[Darkwood]

As above you openly express your inexperience in this field yet you are willing to sign someone else work off, you may be digging yourself a big hole here I personally wouldn't write off a job because i have a piece of paper that says I can if I know in myself im not experienced enough to do so.

That aside im assuming that other than the sub cable of choice been a 10mm T&E then i assume you have calculated that the earth is adequate in the T&E as its supplying multiple circuits and may require additional earthing.

Also how big is this shed, what is the expected load it seems odd a ring is been done if a radial will suffice.

Need more Info....

E54- agree here 2 Electricians and it ringing bells about the basics of its design something seems wrong here or we are missing something.

 

[GLENNSPARK]

Hi all,
im a recently qualified electrician who is looking for a bit of advice. A friend of mine (also an electrician) has asked for my help on one of his jobs. The job is feeding a sub main distribution board which is located in the porch area. It is only feeding two circuits, one being a 32a small ring circuit in the shed in the garden, and the other being a 6a lighting circuit feeding the light in the porch. The problem I'm having is that my friend is wanting to feed the board using a 10mm PVC twin running it under the flooring from the main fuse board. He's saying that he thinks it's fine running it straight from board to board. However I'm sure that along the lines somewhere you have to run it through a spur? The run is only around 10-15 metres from board to board but I just wanted to check before my name would be going on the test sheet. Sorry if this is a dumb question however I don't do much domestic work in my job.
thanks for any help.

eh?.....

 

[aj2304]

Something not quite right here!! A couple of questions, ...why is this CU that is supplying a garage FRC located in the house porch and not in the shed?? How are you intending to wire this shed FRC from the porch CU?? Why can't the porch light be fed from the existing lighting circuit??

The ring and the lights are already previously wired. the only thing we were rewiring is the feed to the porch CU. As it was previously fed using 2.5mm.

 

[aj2304]

eh?.....

He needs help pulling a new feed in? What's with the Eh?

 

[Octopus]

Self Certification involves the design, installation and testing of YOUR work - go down the slippery slope of signing off cowboys work and you will need a horse too.

 

[MDJ]

Hi all,
im a recently qualified electrician who is looking for a bit of advice. A friend of mine (also an electrician) has asked for my help on one of his jobs. The job is feeding a sub main distribution board which is located in the porch area. It is only feeding two circuits, one being a 32a small ring circuit in the shed in the garden, and the other being a 6a lighting circuit feeding the light in the porch. The problem I'm having is that my friend is wanting to feed the board using a 10mm PVC twin running it under the flooring from the main fuse board. He's saying that he thinks it's fine running it straight from board to board. However I'm sure that along the lines somewhere you have to run it through a spur? The run is only around 10-15 metres from board to board but I just wanted to check before my name would be going on the test sheet. Sorry if this is a dumb question however I don't do much domestic work in my job.
thanks for any help.

You won't find a spur on the UK market designed for Domestic use which can handle a 10mm2 Cable, the whole thing stinks, the Design is poor, the Questions even worse. Forget the whole thing and go back to square one.

 

[Sintra]

I would really have thought that 2 "qualified" sparks should be able to design and install a domestic sub main.

 

[Marvo]

go back to square one.

I'm inclined to agree, There has to be a better way to do this.

 

[Sintra]

Thread closed on ops request.