Definition of 'new circuit' (new notifiability - England)

[JohnW2]

This question was touched on in a recent thread, but I’m not sure that a definitive conclusion was reached - and a point in question has arisen in another thread.

One of the few things which remains notifiable (in England) is the provision of a ‘new circuit’, which therefore begs the question as to exactly what this means.

Part 2 of the regs defines ‘a circuit’ as an assembly of electrical equipment supplied from the same origin and protected against overcurrent by the same protective device(s). ‘Origin’ (or 'origin of a circuit'), per se, is not defined. ‘Origin of an installation’ is defined (in the obvious way), but that’s a bit different.

My interpretation, which I think is probably a common sense one, is that ‘a new circuit’ is one that was previously absent and which originates from a new (previously absent or unused) OPD in a CU, switch-fuse or equivalent which is supplied directly from the installation’s meter (i.e. supplied from 'the origin of the installation'). Do others share that view?

The potential ‘silliness’ relates to new wiring connected to an existing circuit via an FCU – since it might be possible to interpret this as a ‘new circuit’, originating at the FCU and specifically protected by the FCU’s fuse. However, that would even apply to a fused spur connected to a ring or radial final circuit, which surely was not intended to be a ‘new circuit’ (that was non-notifiable even under pre-April rules). Do others agree with me that any such interpretation would be silly?

The main reason for this post is that a grey area has recently shown itself in a current thread. Someone wishing to install a supply to an outhouse from an existing supply to another outhouse has been advised that it would be notifiable, presumably on the basis that it is a ‘new circuit’ (rather than an addition to an existing circuit) .... but is it???

Kind Regards, John

 

[jamesmcbride]

I share the view that ‘a new circuit’ is one that was previously absent and which originates from a new (previously absent or unused) OPD in a CU, switch-fuse or equivalent which is supplied directly from the installation’s meter (i.e. supplied from 'the origin of the installation')

I know this is wondering off topic a little already, but I have been thinking recently whether or not this scenario should be notified or not:

• 
  A new socket outlet for general use is to be added to an existing RFC.
  
  The existing installation does not have any RCD's, so therefore you would either need to add an RCD socket, an RCD FCU or add RCD protection at the origin of the installation.
  
  The consumer unit is compatible with RCBO's, so it would be possible to upgrade the whole circuit to have RCD protection without making any other changes in the consumer unit other than replacing the MCB with an RCBO.

Obviously an EIC would be issued, but should it be notified?

 

[JohnW2]

I share the view that ‘a new circuit’ is one that was previously absent and which originates from a new (previously absent or unused) OPD in a CU, switch-fuse or equivalent which is supplied directly from the installation’s meter (i.e. supplied from 'the origin of the installation')

Thanks. I'm glad you agree.

I know this is wondering off topic a little already, but I have been thinking recently whether or not this scenario should be notified or not:

• A new socket outlet for general use is to be added to an existing RFC.
  The existing installation does not have any RCD's, so therefore you would either need to add an RCD socket, an RCD FCU or add RCD protection at the origin of the installation.
  The consumer unit is compatible with RCBO's, so it would be possible to upgrade the whole circuit to have RCD protection without making any other changes in the consumer unit other than replacing the MCB with an RCBO.

Obviously an EIC would be issued, but should it be notified?

Why should it be notified? No matter how you do it, it's clearly not a 'new circuit', and equally does not fall into either of the other two remaining (in England!) categories of work requiring notification. Even under pre-April rules, it certainly would not have been notifiable if you'd used an RCD socket or RCD FCU, and it is (IMO) even debatable as to whether changing the circuit's MCB to an RCBO would have been. However, under the new rules, I really don't see any reason why it should be notifiable, no matter how you do it - do you?

Kind Regards, John

 

[jamesmcbride]

Why should it be notified? No matter how you do it, it's clearly not a 'new circuit', and equally does not fall into either of the other two remaining (in England!) categories of work requiring notification. Even under pre-April rules, it certainly would not have been notifiable if you'd used an RCD socket or RCD FCU, and it is (IMO) even debatable as to whether changing the circuit's MCB to an RCBO would have been. However, under the new rules, I really don't see any reason why it should be notifiable, no matter how you do it - do you?

Kind Regards, John

No, I agree that an RCD socket and and RCD FCU would not constitute a new circuit.

What I am debating, is whether replacing an MCB with an RCBO would be a new circuit, on the basis that you are technically introducing a new protective device.

 

[ban-all-sheds]

Part 2 of the regs defines ‘a circuit’ as an assembly of electrical equipment supplied from the same origin and protected against overcurrent by the same protective device(s).

Will that be Part 2 of a document which is not mentioned at all in the legislation?

My interpretation, which I think is probably a common sense one, is that ‘a new circuit’ is one that was previously absent and which originates from a new (previously absent or unused) OPD in a CU, switch-fuse or equivalent which is supplied directly from the installation’s meter (i.e. supplied from 'the origin of the installation'). Do others share that view?

The potential ‘silliness’ relates to new wiring connected to an existing circuit via an FCU – since it might be possible to interpret this as a ‘new circuit’, originating at the FCU and specifically protected by the FCU’s fuse. However, that would even apply to a fused spur connected to a ring or radial final circuit, which surely was not intended to be a ‘new circuit’ (that was non-notifiable even under pre-April rules). Do others agree with me that any such interpretation would be silly?

The main reason for this post is that a grey area has recently shown itself in a current thread. Someone wishing to install a supply to an outhouse from an existing supply to another outhouse has been advised that it would be notifiable, presumably on the basis that it is a ‘new circuit’ (rather than an addition to an existing circuit) .... but is it???

No.

 

[JohnW2]

Why should it be notified? No matter how you do it, it's clearly not a 'new circuit', and equally does not fall into either of the other two remaining (in England!) categories of work requiring notification. Even under pre-April rules, it certainly would not have been notifiable if you'd used an RCD socket or RCD FCU, and it is (IMO) even debatable as to whether changing the circuit's MCB to an RCBO would have been. However, under the new rules, I really don't see any reason why it should be notifiable, no matter how you do it - do you?

No, I agree that an RCD socket and and RCD FCU would not constitute a new circuit. What I am debating, is whether replacing an MCB with an RCBO would be a new circuit, on the basis that you are technically introducing a new protective device.

I see no reason why changing the protective device would make it a 'new circuit'. As BAS has pointed out, the legislation itself contains no definitions, but if we look to the BS7671 definitions as the next best thing, I don't really see that changing the protective device would make it a 'new circuit'. Indeed, the BS7671 definition of 'a circuit' only refers to 'common' overcurrent protection - so, say, changing a 32A MCB to a 32A RCBO would not have changed that at all (not really any different from replacing a faulty 32A MCB). As I said, even under the old rules, I think it may have been debatable as to whether it was notifiable.

What do others think?

Kind Regards, John

 

[JohnW2]

Part 2 of the regs defines ‘a circuit’ as an assembly of electrical equipment supplied from the same origin and protected against overcurrent by the same protective device(s).

Will that be Part 2 of a document which is not mentioned at all in the legislation?

Indeed it would - but in the absence of any definitions in the legislation itself, the 'next best thing' would seem to be to look to the BS7671 definitions, particularly given that we know (from Approved Doc P) that the legislators appear to believe that compliance with BS7671 is one way of complying with the legislation.

My interpretation ... Do others share that view?

The potential ‘silliness’ relates to ... Do others agree with me that any such interpretation would be silly?

Glad you agree.

The main reason for this post is that a grey area has recently shown itself in a current thread. Someone wishing to install a supply to an outhouse from an existing supply to another outhouse has been advised that it would be notifiable, presumably on the basis that it is a ‘new circuit’ (rather than an addition to an existing circuit) .... but is it???

No.

As will presumably will have been apparent (my question was almost rhetorical), that is also my view, but I'll be interested to hear if others agree.

Kind Regards, John

 

[securespark]

In my job, if we swap a fuse for a CB, technically, we class it as changing the characteristics of the circuit, and have to fill out an EIC.

 

[JohnW2]

In my job, if we swap a fuse for a CB, technically, we class it as changing the characteristics of the circuit, and have to fill out an EIC.

I suppose that's fair enough - at least in the sense that it is technically/literally true. However, in the present context, "changing the characteristics of a circuit" is not, per se, notifiable work.

Kind Regards, John

 

[ericmark]

My interpretation, which I think is probably a common sense one, is that ‘a new circuit’ is one that was previously absent and which originates from a new (previously absent or unused) OPD in a CU, switch-fuse or equivalent which is supplied directly from the installation’s meter (i.e. supplied from 'the origin of the installation').

I think that is a sensible approach. The idea of calling the ring a "final ring circuit" would point to the idea that anything taken from the circuit is on in its self a new circuit.

Yet reading the definition then also clearly a FCU is a new circuit using BS7671 definition, also clearly this is not considered as a new circuit as far as Part P goes.

So looking at common sense why should a new circuit require notifying.
1) Requires assess to the consumer unit.
2) Requires design selecting cables, MCB ect.
3) Requires assess to the buzz bars of the consumer unit.
Both one and two would exist if one was to add a spur from an existing MCB in the consumer unit so the extra danger and likely reason would be assess to the buzz bars.

So the question is where a MCB/Fuse/RCBO already exists but has nothing connected to it would that be considered as a new circuit? It is clearly no good looking at BS7671 as that clearly would include a FCU so we have to use common sense.

So if someone was to fit a double socket next to the consumer unit and spurs it from the 32A ring circuit then it's not a new circuit. If latter he moves the wire from the 32A MCB to an existing unused 16A MCB that is also not a new circuit. So how can connecting to an existing MCB used or unused be considered as a new circuit?

Again looking at the common sense do you really think if there is the slightest chance that a DIY guy can do work without paying the LABC their huge fees that he is going to pay them?

So in real terms the new circuit is a non starter. Any DIY guy is going to say something like "It was for an old immersion heater I just re-routed for another function.

So next is the scheme member electrician. Here we have something very different. This guy is not controlled by Part P he is controlled by the scheme provider. So he has to inform his scheme provider with what they say he has to do. It is down to the scheme operator to say what is a circuit.

So if the scheme operator says a FCU is not a new circuit then that's that. In the same way they can stipulate if using an existing MCB is a new circuit where the cables do not follow the same route as original.

Fitting a CU or fitting new items within the area defined in a bathroom is clearly reportable new circuit however is down to scheme providers to define and as it's a health and safety issue this would have to be in writing. It does not matter what we think it means as far as a scheme member goes it is down to written instructions from the operator of the scheme.

The same goes for distribution within a sub area of the home. As already stated using FCU is not considered under Part P as a new circuit so one could for example use an old cooker supply and take it into the garage to fed a daisy chained set of FCU's each in turn supplying different circuits.

Or one could use a consumer unit with MCB/RCBO's to do the same.

Again it's definitions when fed from the main consumer unit is a second unit a consumer unit or distribution board? In the same way as a rod in the ground can be with TT an earth electrode but when converted to TN it becomes a extraneous-conductive-part, so when a consumer unit is not fed directly from the DNO supply it could be considered to change name to distribution unit. It does not really matter what the manufacturer names it what matters is what it is used for.

Again as far as the DIY man goes he is not going to pay the huge fees if he can get away without but for the scheme member he must do as the scheme provider tells him.

I of course realise that most scheme members will not like the idea of it being required that he notifies but the DIY man does not need to bother and it would cause continual arguments on forums like this.

So what I would suggest is as electricians we ignore what the DIY man can get away with and quote what the scheme providers say in their literature to there members. However to do that those of us who are not members will need to see this literature so we are all singing from the same sheet.

So what do the scheme providers tell their members. Can the instructions be reproduced here or a link provided so we can read them please.

 

[ban-all-sheds]

this is not considered as a new circuit as far as Part P goes.

Nothing is. Part P does not concern itself with things like that.

So next is the scheme member electrician. Here we have something very different. This guy is not controlled by Part P he is controlled by the scheme provider.

Untrue - just like anybody and everybody else doing any work whatsoever on fixed electrical cables or fixed electrical equipment located on the consumer’s side of the electricity supply meter which operate at low or extra-low voltage and are—
(a) in or attached to a dwelling;
(b) in the common parts of a building serving one or more dwellings, but excluding power supplies to lifts;
(c) in a building that receives its electricity from a source located within or shared with a dwelling; or
(d) in a garden or in or on land associated with a building where the electricity is from a source located within or shared with a dwelling,

he is bound by Part P.

As already stated using FCU is not considered under Part P as a new circuit

And as already stated here Part P does not specify what is or is not notifiable, who may or may not do work without notifying etc.

Part P is purely about safety.

 

[JohnW2]

My interpretation, which I think is probably a common sense one, is that ‘a new circuit’ is one that was previously absent and which originates from a new (previously absent or unused) OPD in a CU, switch-fuse or equivalent which is supplied directly from the installation’s meter (i.e. supplied from 'the origin of the installation').

I think that is a sensible approach. ... Yet reading the definition then also clearly a FCU is a new circuit using BS7671 definition ...

Not per the approach you've just said is sensible!

...also clearly this is not considered as a new circuit as far as Part P goes.

[I presume you mean the Building Regs, rather than 'Part P']. It is certainly true that, even prior to April 6th in England (and still in Wales), addition of a fused spur to a final circuit was permitted without notification.

So looking at common sense why should a new circuit require notifying.
1) Requires assess to the consumer unit.
2) Requires design selecting cables, MCB ect.
3) Requires assess to the buzz bars of the consumer unit.

That might make sense (as the reason for 'new circuits' being notifiable) were it not for the fact that there are countless electrical works which no longer require notification (in England) but which involve one, two or all three of those things - e.g. replacing an MCB (or even a main switch/incomer!) is clearly no longer notifiable in England.

So in real terms the new circuit is a non starter. Any DIY guy is going to say something like "It was for an old immersion heater I just re-routed for another function.

In general, it's not really a 'non-starter'. If it is completely new wriring which originates from a new (previously not present) MCB/RCBO in the main/only CU, then I don't think that any of us could find a way of arguing that it was not a 'new circuit'.

So next is the scheme member electrician. Here we have something very different. This guy is not controlled by Part P he is controlled by the scheme provider. So he has to inform his scheme provider with what they say he has to do. It is down to the scheme operator to say what is a circuit. ... So if the scheme operator says a FCU is not a new circuit then that's that.

I very much doubt that a scheme operator can 'over-ride' the Building Regs. If it were to be determined (e.g. by a Court) that the law is to be interpreted as meaning that a fused spur is a 'new circuit', then the scheme operator would be stuck with that.

The scheme operators obvioulsy can (and maybe do) offer guidance to their members as regards the interpretation of these 'grey areas' of the legislation (and their guess is as good as ours!) - and I suppose that they could even make that 'guidance' binding on their members, so long as it did not conflict with the law. However, ultimately the scheme member has to comply with the law, regardless of what the scheme operator may say.

So what do the scheme providers tell their members. Can the instructions be reproduced here or a link provided so we can read them please.

It would certainly be interesting to know what (if anything) the scheme operators say to their members about these things. Given that what we're actually talking about is interpretation of the law, I rather suspect that they will be careful 'not to stick their necks out' too far, and therefore may be very guarded/limited in terms of what they say about interpretation of the law. Indeed, for all I know they might totally pass the buck, and simply say that things must be notified if the law says they are notifiable - i.e. effectively passing the buck to the electrician.

Kind Regards, John

 

[flameport]

• 
  A new socket outlet for general use is to be added to an existing RFC.
  
  The existing installation does not have any RCD's, so therefore you would either need to add an RCD socket, an RCD FCU or add RCD protection at the origin of the installation.
  
  The consumer unit is compatible with RCBO's, so it would be possible to upgrade the whole circuit to have RCD protection without making any other changes in the consumer unit other than replacing the MCB with an RCBO.

None of those items are notifiable.
A socket outlet is not a new circuit, and neither is a protective device on it's own.
An RCD in a box is not a consumer unit, and putting a single RCD at the origin of an installation won't comply with BS7671 anyway (although there are circumstances where such an item should be fitted for other reasons, compliant or not).

 

[SimonH2]

Hmm, some interesting scenarios indeed.

Another that comes to mind is :
You have an RFC running off a 32A breaker. You add a second RFC to the same breaker - ie there are now 4 tails in the breaker. This is arguably not a new circuit as the breaker was already there. What if you've split an existing ring, rather than adding a new one ?

Having got this far, what if we drop the tails out of one ring and stick them into a new breaker. The circuit (load of cable with sockets on) already existed, only the breaker is new. So is this a new circuit ?

Now suppose (instead of adding an extra ring) we add one or more sockets on a radial from the same breaker as an existing RFC. Thinking ahead we use 4mm cable. Then at some point we move this to a new breaker. And then we decide we want a 32A socket for the welder and replace the double 13A socket with a 32A BS4343 one.

Lots of "new" there, but arguably not a single new circuit

 

[JohnW2]

You have an RFC running off a 32A breaker. You add a second RFC to the same breaker - ie there are now 4 tails in the breaker. This is arguably not a new circuit as the breaker was already there.

Agreed. IMO not a new circuit.

What if you've split an existing ring, rather than adding a new one ?

Assuming you mean simply chop the ring in half, with both halves becoming radials supplied by the same MCB then, IMO, still not a new circuit.

Having got this far, what if we drop the tails out of one ring and stick them into a new breaker. The circuit (load of cable with sockets on) already existed, only the breaker is new. So is this a new circuit ?

As we've discused, there are no definitions in the Building Regs, but if we go by the BS7671 definition of 'a circuit', this is a different (hence 'new') one, since since it does not share the same OPD.

Now suppose (instead of adding an extra ring) we add one or more sockets on a radial from the same breaker as an existing RFC. Thinking ahead we use 4mm cable. Then at some point we move this to a new breaker. And then we decide we want a 32A socket for the welder and replace the double 13A socket with a 32A BS4343 one.

As above, per BS7671, 'a new (different) breaker' means a separate (hence 'new') circuit.

Lots of "new" there, but arguably not a single new circuit

There is certainly scope for some discussion/'argument' but, as above, if (in the absence of any other definitions/rules/guidance) one goes by the BS7671 definition, then the moment a circuit has a separate 'primary' OPD (i.e. not a 'secondary'FCU or whatever on a circuit which already has a 'primary' OPD), it's a separate circuit, and since it wasn't there before, that probably makes it a 'new circuit'.

As I said at the start, I think the most sensible common sense definition is as simple as that. If a circuit originates from a new OPD (i.e. one which wasn't previously present or being used) in the primary/only CU (or meter-supplied switchfuse), then it's a 'new circuit'. Otherwise it isn't.

Kind Regards, John