what constitutes a new circuit?

[coolhands]

In my own home am I allowed to add an extra socket on the ring main? (no actual increase in number of sockets since I will be removing an unwanted one. So in a sense re-siteing a socket I suppose). Am I allowed to rewire parts of a ring circuit to remove inaccesable junction boxes fitted by previous owners, and unwanted sockets?

I believe I am not allowed to add a new circuit hence the title.

thanks

 

[flyingsparks]

The work you describe is not notifiable.
A new circuit (which is notifiable) is a new supply from the fuse board.

 

[deadshort]

Hi, that is correct. But i would advise you have your worked checked and tested by an electrician with the correct test kit.

Regards,

DS

 

[coolhands]

thankyou

 

[PrenticeBoyofDerry]

It is not illegal for you to install a new circuit, but you must adhere to the notification procedures, set down by building controls.

A new circuit would constitute, installation strating from the fuse board/consumer unit onwards.

You say you are allowed to add/remove sockets, there is a legal responsibility whilst undertaking and commissioning such tasks.

Any new cable buried within walls and new sockets, should comply to the regulations concerning 30mA protection.

 

[ericmark]

It is an interesting question.
From statements made it would seem Part P and IET definitions differ with this so the use of a simple FCU would under 17th Edition form a new circuit but with Part P it does not.

For a populated consumer unit one can argue there are already in existent all circuits so using a MCB/RCBO already fitted it's not a new circuit it's only an extension of an old one. But if the MCB/RCBO does not exist already than it's a new circuit.

However in British law it's up to the courts to decide and until some one is take to court for installing a new circuit using an existing MCB/RCBO no one can give you an answer.

Personally I feel from the consumer unit it is a new circuit even if the MCB/RCBO exists already but I use the IET/BSi BS 7671 for definitions.

The same question comes up with consumer units fitted to garages or sheds these are not that much different to a FCU and if manufactured before 1989 then they are not consumer units so you could fit. This does seem rather crazy you can fit an old Wilex unit which was originally designed for fuses but not a modern one?

What does seem to make sense however is if a minor works certificate will cover than it's not a new circuit if however it requires an installation certificate it is.

I would say for a rented property then one has to ensure all i's dotted and t's crossed and trying to hide behind the writers of Part P lack of grasp on the English language is not really going to help if there is an accident then there will be a court case. But in occupier owned property then the chances of a court case are very slim so all your really worried about is if it's safe.

 

[JohnW2]

Personally I feel from the consumer unit it is a new circuit even if the MCB/RCBO exists already but I use the IET/BSi BS 7671 for definitions.

BS7671 surely defines a circuit as a collection of equipment supplied from a common origin and protected by the same OPD? If one uses that definition, an addition originating from an existing MCB/RCBO would clearly not be a 'new circuit'.

In common sense terms, it would be silly to suggest that a spur (from a ring final) or branch (from a radial final) originating at the CU was a 'new circuit', whereas the same would not be a 'new circuit' if it originated anywhere else in the existing circuit.

Kind Regards, John

 

[skotl]

...Personally I feel from the consumer unit it is a new circuit even if the MCB/RCBO exists already but I use the IET/BSi BS 7671 for definitions.

The same question comes up with consumer units fitted to garages or sheds these are not that much different to a FCU...

That's interesting.
So we have a 17th ed. CU in the house and last year the electrician ran SWA from the house CU to a small CU in the garage.

The garage's CU has a spare way so do you think that still counts as a "new circuit" if I add an MCB and a new radial (probably a 16A socket, if that's relevant). Your suggestion that the garage run is effectively a FCU would suggest that I would be extending an existing circuit rather than adding a new one.

Thoughts?

 

[JohnW2]

That's interesting. So we have a 17th ed. CU in the house and last year the electrician ran SWA from the house CU to a small CU in the garage. ... The garage's CU has a spare way so do you think that still counts as a "new circuit" if I add an MCB and a new radial (probably a 16A socket, if that's relevant). Your suggestion that the garage run is effectively a FCU would suggest that I would be extending an existing circuit rather than adding a new one. Thoughts?

I would personally call that extending an existing circuit - since I believe that the intention is that having a common 'primary' OPD (in the house CU) which makes everything 'a circuit'. As has often been discussed, if you took the opposite view, it would mean that every FCU would create 'a new circuit' - and I feel sure that was not the intention of those who wrote the regs. Of course, it doesn't really matter much in terms of the regs themselves (it's really just a semantic issue), so they probably didn't think too deeply about the wording - it's only because of its relevance to 'notifiability' (in England) that it has become an issue.

Kind Regards, John

 

[flameport]

This situation occurred the other day:

Two CUs, both main switch with all RCBOs. One for usual circuits, the other for off peak storage heaters.
Storage heaters being removed, so the RCBOs in the off peak CU were moved into the other CU, and the circuit cables reconnected.
The cables were not shortened/lengthened or changed in any way, the same RCBOs were used.
The DP switches at the ends of the circuits were changed to single socket outlets.

New circuits or not?

 

[JohnW2]

Two CUs, both main switch with all RCBOs. One for usual circuits, the other for off peak storage heaters.
Storage heaters being removed, so the RCBOs in the off peak CU were moved into the other CU, and the circuit cables reconnected. The cables were not shortened/lengthened or changed in any way, the same RCBOs were used. The DP switches at the ends of the circuits were changed to single socket outlets. ....... New circuits or not?

Common sense says no (not new circuits) - changing storage heaters to sockets, per se, would certainly not (in my book) make them 'new circuits'.

In terms of regs, who knows. If one takes the regs literally, and given that you say that you used the same RCBOs (as in the other CU), they would still seem to be the same 'circuits' that they always were (i.e. not 'new circuits'). I suppose there might be more (IMO silly!) room for argument if you used new/different RCBOs - but that would be daft, since it would imply that replacing an MCB or RCBO would constitute 'installing a new circuit' - which it clearly isn't!!

IMO, a case for allowing common sense to prevail!

Kind Regards, John

 

[ericmark]

I have I thought made it clear BS 7671 and Part P use a different definition with BS 7671 using a FCU in the main means you have formed a new circuit.

Personally I feel if the work can be covered with a Minor Works Certificate then not a new circuit.

If however it requires an Installation Certificate then it is.

Now the Minor Works gives a single slot to enter details for the protective device so for a consumer unit with a single MCB/RCBO then you could use a Minor works so not a new circuit.

However with "flameport" example you would need to complete a Minor Works for every MCB added to or use an Installation certificate and include all circuits in one. Clearly when all on the same day and part of the same job then an installation certificate would be the norm so counted as new circuits.

This has been the case of course with a complete re-wire. With no changes and retaining the same CU with the exception of bathroom one could do a circuit a week and 10 weeks latter have 10 Minor Works certificates and not need to register.

However the time when we see what the courts say is when something goes wrong. If some one if killed then all this paper work is sized the court decides. So in real terms you have to consider if you were one of the 12 would you say he was write or wrong?

In real terms to re-wire means adding RCD protection so it will likely need a new consumer unit so no option but to register the work.

 

[ericmark]

Two CUs, both main switch with all RCBOs. One for usual circuits, the other for off peak storage heaters.
Storage heaters being removed, so the RCBOs in the off peak CU were moved into the other CU, and the circuit cables reconnected. The cables were not shortened/lengthened or changed in any way, the same RCBOs were used. The DP switches at the ends of the circuits were changed to single socket outlets. ....... New circuits or not?

Common sense says no (not new circuits) - changing storage heaters to sockets, per se, would certainly not (in my book) make them 'new circuits'.

In terms of regs, who knows. If one takes the regs literally, and given that you say that you used the same RCBOs (as in the other CU), they would still seem to be the same 'circuits' that they always were (i.e. not 'new circuits'). I suppose there might be more (IMO silly!) room for argument if you used new/different RCBOs - but that would be daft, since it would imply that replacing an MCB or RCBO would constitute 'installing a new circuit' - which it clearly isn't!!

IMO, a case for allowing common sense to prevail!

Kind Regards, John

Interesting if you say you can use an installation certificate even when the work does not involve new circuits? In which case how do you define a new circuit assuming a fully populated CU?

In the past before Part P I would often use the ways available but if short of room then share ways.

I just think Part P is unworkable without definitions.

 

[EFLImpudence]

What has the type of certificate got to do with it.

Work may be done on an existing circuit for which you may want to record details which are only on an EIC, therefore one would be used.

 

[JohnW2]

I have I thought made it clear BS 7671 and Part P use a different definition with BS 7671 using a FCU in the main means you have formed a new circuit.

You may think you have made it clear, but I don't understand what you are talking about - Part P contains no definitions and even Approved Doc P contains no relevant definitions.

Personally I feel if the work can be covered with a Minor Works Certificate then not a new circuit.

That appears to be back-to-front in terms of BS7671 - which says that you can use a MWC if a 'new circuit' is not involved (although you are free to use an EIC if you wish). If you want to invoke it 'your way around', how are you going to decide whether a MWC is appropriate?

Kind Regards, John