ring at end of radial

[harrymonkfish]

hi there

I have been asked to complete a 2nd fix, the 1st fix was completed by an electrician who has apparently 'disappeared' without a trace.

The thing is, there are two circuits wired in 6mm T&E on 32mcb's that then jump down after a run of about 6 metres to 2.5mm T&E and then into socket rings.

comments please.

thanks
harry

 

[Sintra]

hi there

I have been asked to complete a 2nd fix, the 1st fix was completed by an electrician who has apparently 'disappeared' without a trace.

The thing is, there are two circuits wired in 6mm T&E on 32mcb's that then jump down after a run of about 6 metres to 2.5mm T&E and then into socket rings.

comments please.

thanks
harry

Where abouts does the 6mm jump down to 2.5mm is this a connection at a socket?

 

[WayneL]

Gonna go out on limb here and say, although not normal practise, technically there's nothing wrong with it.

If you think about it, it's no different to having a 6mm distribution circuit to a one way CU enclosure, with a 32A breaker in it - then wiring your ring final out of the breaker.

In this instance your protective device is at the start of the distribution circuit and you've done away with the CU

I may be wrong - maybe someone else can think of a reason why you can't do it

As an after thought, you would of course have to do your ring-final continuity tests at the JB where it steps down to 2.5 mm

.
Sorry about the double posting, but I have thought of something else:

The regs do state that a ring final circuit starts and finishes at the distribution board (pg362) so if you're gonna be signing it off as 'complies with BS7671' then it isn't allowed

 

[harrymonkfish]

the jump down is in a junction box in the ceiling void.

 

[Bobby B]

Run away!!!!!!!!!!!!!!!!!!!!!!

 

[Guest123]

I would agree with Wayne in that it doesn't comply with BS7671 so technically you couldn't sign it off as being.

Would it be a noted departure perhaps??? Maybe give your scheme provider a call for their views.

 

[WayneL]

Would it be a noted departure perhaps??? Maybe give your scheme provider a call for their views.

Good point, Len. You can intentionally depart from the Regs, so long as the resulting degree of safety is

no less than if you had complied with them - in this case I don't think safety is compromised.

I don't understand why he did it though - why not just run two 4mm radials and be done?

 

[MarcT]

As stated previously you would need to ensure compliance or an acceptable departure from BRB.
Particularly with regards to the adiabetic equation regarding mixed sizes of c.p.c

 

[Guest123]

Maybe an adiabatic to ensure the CPC would be suitable for the fault current.


Edit....Marc beat me to it.

 

[rocker]

Why the hell would someone do this? What possible benefit would it give the installer? I see stuff like this and just think 'what the hell were you thinking?'

Mate, it's six meters. Balls to whether its safe or allowed, draw the customer's attention to it, say you are going to be fixing it and get it standardised. It is causing unnecessary confusion.

 

[Bobby B]

Why the hell would someone do this? What possible benefit would it give the installer? I see stuff like this and just think 'what the hell were you thinking?'

Mate, it's six meters. Balls to whether its safe or allowed, draw the customer's attention to it, say you are going to be fixing it and get it standardised. It is causing unnecessary confusion.

Yeah thats exactly what I'd do to

 

[markythesparky]

I agree with the last two posts.

Why are you even asking. just tell the client that the previous sparks cocked it up and it needs sorting to comply with regs.

Itll thenbe done properly and it more work for you.

 

[Cobraman]

It really is not worth pondering over, with all the issues it raises like the mixed cpcs and deviation from the regs a replacement to a standard circuit is better for everyone, there will come a time when this will cause a reall headache for someone trying to add or modify the circuit at a later stage.

We have a whole range of standard circuits to use that are simple comply and work fine, I just can't understand how someone would install this and think this is a good idea?

Keep it simple.

 

[harrymonkfish]

thanks for all your replies.

it is being re-wired.

harry

 

[baldsparkies]

thanks for all your replies.

it is being re-wired.

harry

Thats the right answer 10/10.