Electrical wiring

[YorkieJohn]

Is it ok to put a junction box in a ring main then wire to a fcu with a 13amp fuse for a cooker hood then from that fcu wire to another fcu with a 5amp fuse for 2 under cabinet strip lights ?

[The Builder]

Yes, John. As long as you have the fused spur from the ring (use 2.5mm or 1.5mm cable depending on length of run and location of run), then you can loop-on forever.

[TOWIE]

Actually, Mr. Den was reading this at work and has just phoned me - apparently you cannot spur off a ring main with 1.5 T & E cable the ring main has a 32amp fuse in it.

You cannot loop on forever on a ring main.

The Cooker Hood should be fused at 3 or 5amp from the FCU as well as the lights.

[heathfield]

Builder said it was ok, but did stipulate - as long as the spur was fused.

[Davethedog]

You do know under legislation any electrical work in your house should be carried out by a qualified sparks.

I realise that it may be "nanny state" but should you have an electrical fire it may invalidate your insurance.

[heathfield]

In fact, some DIY electrical work is permitted, but it should be afterwards checked by a qualified electrician. See a list here...

http://electricalhelp...l_work_you_can_do.htm

[LCDMAN]

It's in a kitchen so it's notifiable work under Part P of the Building Regs.

[The Builder]

OK Yorkie. I need to clear this up. Under the new(ish) 17th editions, it is now perfectly acceptable to loop on.......... because ............ the whole "chain" is protected by the initial 13A fuse.

In fact, it has been common practice for ever, to spur a ring main for e.g. a light fitting........... using a 5A fuse and 1mm cable!!!! The cable is protected by the 5A fuse.

I guess TOWIE is confusing this with a simple UNFUSED spur, which, MUST be in 2.5mm cable.

I remember that this area caused some confusion when I did the Domestic Installer course. The tutor made a point of saying that, it is now permitted to loop on as much as you like as long as it is covered at the "head" of the spur with a FUSE.

[The Builder]

Also, as LCDMAN has pointed out, it's a NEW addition to a circuit, so it is notifiable. Thank you to him, I should have said that as well.

[BRIGHT SPARK]

yorkie...if you need to ask these questions then dont touch it!!
TB...there was no ref in the question about putting a fuse at source only for the cooker hood...so the answer is NO.
As you said if a 13a fuse was put at source then it would comply but its a bit B&Q!

[The Builder]

Now I'm confused, Brighty :o(
Perhaps I misunderstood the Q. I didn't mean a 13A fuse in the consumer unit........... I thought he meant in the fused spur. That would surely comply?
Sorry if I've read it wrong, but I was taught that a fused spur (13A) could be extended.

[The Builder]

Right ............ now I'm quoting verbatim from the IEE On-Site Guide (the electricians bible)..............

Appendix 8 8.2.4 Spurs

"A fused spur should be connected to the circuit through a fcu, the rating of the fuse in the unit not exceeding that of the cable forming the spur and, in any event, not exceeding 13A"

It would then follow that, as this spur is fuse protected ...... further extension (radial circuit) is also protected.

[BRIGHT SPARK]

TB....you are correct but the question did not imply fitting a FCU at the connection point of the proposed radial spur.Only 2 FCU outlets were mentioned and 3 would be needed...1 at the source 13a..1 at the cooker hood 3a and 1 for the lights 3a.

[The Builder]

My fault, Brightness ............ I knew you'd clear it up eventually :o)
I missed the point about the junction box in the ring ...... that's where the 13A fcu should be, then daisy chain from there. Thanks.

[BRIGHT SPARK]

Yorkie....legalities apart.....cut the ring...put a 32a jb on each end...take a 2.5 twe to the first fcu supply term..then to the second fcu supply term..then back to the second jb.Carry out all required testing..energise and carry out a earth fault loop test and rcd test.

[BRIGHT SPARK]

PS.....TB...at this rate I might qualify as a Merc driver instead of a deluded BMW driver:----)))]