Extending ring main

[peetee]

Hi everyone I need some advice my daughter is having an extension can I extend the ring from one of the socket outlets by crimping line neutral and earth of one of the two cables do this in the backbox then drill through back box and feed the new cable through the back box into the extension carry on putting in new sockets and then terminate the last socket back in socket outlet back at start and crimp these in the same backbox where I started?

Any advice would appreciated

 

[m4tty]

Sounds good make sure you use a grommets where you drill through backbox tho

 

[fletchflash]

You wouldn't need to crimp twice though. Once to send the cable to the extension, then the return cable would be into the original socket terminals

 

[PC Electrics]

You can. Whether you should is another matter.

What, if any, assessment has been made regarding the safety and suitability of the existing ring for such an extension? What is the likely effect on the load profile?

Also, as this is for an extension, what is the BCO expecting? Are you having the new work inspected by the Authority afterward or is the BCO expecting it to be carried out by a registered electrician?

These things should be checked before jumping straight in.

 

[spinlondon]

You should check the condition and safety of any circuits you intend altering, or making additions to before commencing work.

You would also have to ensure that the new work complied with the current Regulations, e.g. that the socket-outlets have RCD protection.

As for what BCO is expecting, it would depend on whether the extension is intended to be a special location, such as a kitchen or bathroom.

There is no requirement to notify alterations or additions to existing circuits, as long as the work is not in a special location.

 

[peetee]

I am training to be Domestic installer so are you saying this would be no good as part of my assessment as its not a new circuit? can I use same principal to extend what will be taking power from excisting ceiling rose through wall to new upstairs? what is BCO?

 

[green-hornet]

BCO = Building Control Office

It is permissable to extend the circuits as you say, and it could be used as one of your assessment jobs. The extra loading would in honesty be very minimal but worth investigating, any fault on the old wiring would make the new wiring just as vunerable.

I prefer to put seperate circuits in for any extention, as this way it saves all the hassle with the old stuff.

The extention may be under building control so you would need to notify them that the electrical work is being carried out by a non part p registered electrician before the work starts, they may waive any fee if you can show them your application to a part p provider and your certificates, otherwise you will have to pay.

 

[Apache]

The extension may be under building control so you would need to notify them that the electrical work is being carried out by a non part p registered electrician before the work starts,

Not if, like Spin says, it's not an SL and not a new circuit?

 

[batty]

I very very rarely would extend a circuit to feed an extension a new circuit or circuits would be installed. More information about what extension comprises is needed to judge wether you should extend ring main and lighting circuit.

 

[green-hornet]

Not if, like Spin says, it's not an SL and not a new circuit?

Most planning applications and associated paperwork will require that the wiring is carried out to building control approval.

I know some inspectors that will not sign off the building until they have seen the EIC's.

One BCO who I deal with in my area, I email all my certs so he has a copy of them for his records.

I also find that it is almost always neccessary to include at least one new circuit, smoke alarms being the most common. I am also very reluctant to extend an unknown circuit that can not be traced throughout its route for conformity, which is one of the reasons I always put new circuits in for any extention.

 

[Mark2spark]

Well I know there's a lot of unknowns here and that the work hasn't actually been done yet, according to OP, but (@Greenhornet) clearly the BI is overstepping his authority if he wants to investigate non notifiable works.

Neither would there be a EIC for extending a ring, it'd be a MWC.

"Most planning applications and associated paperwork will require that the (notifiable works) wiring is carried out to building control approval."

Does that look better?

Neither is a new circuit for a smoke alarm a neccessity.

What may well be valid is that the ring (or indeed the lighting circuit briefly touched upon) to be extended is not rcd protected, and therefore a change to cpd would involve notifiable works.

 

[green-hornet]

I agree almost 100%

However I have never extended a circuit for an extention so it would be rare for me to make out a MWC, as for the smokes yes you can take the circuit from the downstairs lighting and extend this for the extention I do find though that r1+r2 readings and Zs readings get very high with the introduction of extra cable lengths, and most cheap builds use 1.00mm cable so the derating for the new 1.5m depth insulation (thats an exageration) but looks that deep these days. I just never have the confidence to extend someone elses work and prefer to start afresh

 

[M107]

Neither is a new circuit for a smoke alarm a neccessity.

It is in my area as the BC insist on sererate circuit for smokes if none are already present in the old part of property thats being extended.

Insist on smokes one at top & bottom of all stairs (loft conversions) + a heat detector in the kitchen. If the property has a log fire/burner in any rooms they insist on heats there also.

 

[Mark2spark]

It is in my area as the BC insist on sererate circuit for smokes if none are already present in the old part of property thats being extended.

Building Inspectors, huh? :_|

Sometimes it's easier to do a new circuit anyway, but if I was in an argumentive mood I think i'd photocopy the relevent part and hand it over, if he still insisted i'd tell him he's required to sign the design part of the cert