Extending a Ring Circuit

[winston1]

Sigh

What's up John? Heat getting to you?

 

[JohnW2]

sigh²

 

[Taylortwocities]

What's up John? Heat getting to you?

Your input reminds me of fairy stories.


Grimm

 

[Jupiter01]

UPDATE: I have a run in a new and separate RFC for my 3 double sockets. I managed to source a new breaker for this SCHUPA Consumer Unit so need to double up an existing MCB.

I used a drill and chisel bit on my hammer drill to keep these chases as tight as possible. Struggled…

The easifill beautifully smoothed it all out.

I’d welcome your feedback and thanks for all your help.

 

[Taylortwocities]

New and separate circuit is notifiable work. How are you going to notify this work if you are not registered with one of the Competent Person Schemes?

How have you carried out the required continuity, insulation resistance, EFLI and other tests on this new circuit?

 

[Jupiter01]

New and separate circuit is notifiable work. How are you going to notify this work if you are not registered with one of the Competent Person Schemes?

How have you carried out the required continuity, insulation resistance, EFLI and other tests on this new circuit?

I own a MFT and will do the Continuity, Insulation Reistance and RCD tests. I then have a local sparky that will certify it and do the necessary admin.

 

[ericmark]

How are you going to notify this work if you are not registered with one of the Competent Person Schemes?

It has always been permitted to use the LABC, and in England you can get third party inspectors, although not in Wales, the new circuit seems to be a bit vague, as it seems adding a FCU is not classed as a new circuit, I have one cable feeds a back box, can't remember if blanking plate or FCU, I would guess it did feed an outside socket at one time, so was likely once a circuit, so fitting an outside socket would not be a new circuit, although still notifiable.

But at what point is it new, with a fully populated CU but only ¾ used, would the adding of a socket or a other to the existing overload device be a new circuit, technically it is new, as never been a full circuit before, but then so is adding a FCU.

Technically if I don't use a socket it is not a circuit, so if first time it is used is 5 years latter, then even if been there 5 years it is now a new circuit.

However in real terms when an all RCBO CU is fitted the RCD part of the RCBO needs testing, and to test it you make a circuit, so once fitted and tested the circuit to the RCBO is not new any more. The whole Part P thing is silly, due to way written, should have been same as gas, and only requiring registering if you charge to do the work, what is far more important is testing to ensure it is safe.

The schedule of test results serves as a check list to ensure all is tested, you can't fill in the tripping time for the RCD if not measured, or the loop impedance readings, or R1 + R2 with a ring final. OK there are some things the test sheet does not ask for, like volt drop, but ring final circuit continuity (Ω) can be used to work this out.

What I was surprised at when doing the C&G 2391 was the examiner did not expect further investigation when readings did not match the cable length, to my mind a socket with 1.2Ω loop impedance when less than a meter from consumer unit with 0.35Ω loop impedance shows some thing very wrong, and I found it, resistors soldered into the cables.

 

[winston1]

I own a MFT and will do the Continuity, Insulation Reistance and RCD tests. I then have a local sparky that will certify it and do the necessary admin.

You are expecting him to lie and say he designed and tested it then.

 

[Jupiter01]

It has always been permitted to use the LABC, and in England you can get third party inspectors, although not in Wales, the new circuit seems to be a bit vague, as it seems adding a FCU is not classed as a new circuit, I have one cable feeds a back box, can't remember if blanking plate or FCU, I would guess it did feed an outside socket at one time, so was likely once a circuit, so fitting an outside socket would not be a new circuit, although still notifiable.

But at what point is it new, with a fully populated CU but only ¾ used, would the adding of a socket or a other to the existing overload device be a new circuit, technically it is new, as never been a full circuit before, but then so is adding a FCU.

Technically if I don't use a socket it is not a circuit, so if first time it is used is 5 years latter, then even if been there 5 years it is now a new circuit.

However in real terms when an all RCBO CU is fitted the RCD part of the RCBO needs testing, and to test it you make a circuit, so once fitted and tested the circuit to the RCBO is not new any more. The whole Part P thing is silly, due to way written, should have been same as gas, and only requiring registering if you charge to do the work, what is far more important is testing to ensure it is safe.

The schedule of test results serves as a check list to ensure all is tested, you can't fill in the tripping time for the RCD if not measured, or the loop impedance readings, or R1 + R2 with a ring final. OK there are some things the test sheet does not ask for, like volt drop, but ring final circuit continuity (Ω) can be used to work this out.

What I was surprised at when doing the C&G 2391 was the examiner did not expect further investigation when readings did not match the cable length, to my mind a socket with 1.2Ω loop impedance when less than a meter from consumer unit with 0.35Ω loop impedance shows some thing very wrong, and I found it, resistors soldered into the cables.

How would adding a new Circuit on a Garage Consumer Unit (using an existing MCB on main CU) be treated?

 

[Jupiter01]

You are expecting him to lie and say he designed and tested it then.

He knows what I have designed and I have pictures too. He can test again if he wants I suppose.

 

[JohnW2]

... although not in Wales, the new circuit seems to be a bit vague, as it seems adding a FCU is not classed as a new circuit,

You seem to be one of the very few people who have a problem with this, since I think the great majority of people regard it as 'common sense' that adding a FCU does not constitute creating a 'new circuit', and also believe that such was the intent of those who wrote the rules.

The 'problem' you perceive exists because the Building Regulations (which are what create the requirement to notify 'new circuits' in England) do nor define "circuit" or ("new circuit"). For some reason you seem to have chosen to apply the BS7671 definition - which itself was probably not properly 'thought through', because I very much doubt that they intended FCUs to create "circuits".

If you seriously doubt the 'intended interpretation' just look at your own country (Wales). In Wales, there is nothing special about "installing a new circuit", since it is just one of the countless things which are "not exempt from" the general requirement for notification of electrical work. Nevertheless, extending an existing socket by adding an FCU is one of very few things which, in Wales, is explicitly exempt from the requirement for notification.

But at what point is it new, with a fully populated CU but only ¾ used, would the adding of a socket or a other to the existing overload device be a new circuit, technically it is new, as never been a full circuit before, but then so is adding a FCU. Technically if I don't use a socket it is not a circuit, so if first time it is used is 5 years latter, then even if been there 5 years it is now a new circuit.

Again, I think that, for whatever reason, you are ignoring common sense. I think that almost everyone's common sense view of what constitutes "a circuit" requires that, at the least, it involve conductors/cables connecting a source of electricity to loads, or potential loads (as in sockets, FCU, connector plates, JBs etc.). Hence, if there is only an OPD in a CU, with nothing connected to it, that I don't think any sane purpose would regard it as 'a circuit'- so that connecting something to it would count as "creating a new circuit". Conversely, if the OPD is connected, by wiring, to socket(s), then I don't think that any sane person would/could say that it was not "a circuit", even if no loads had ever been connected to the socket(s)/FCU(s)/whatever. As I said, it is, at least in my opinion, really just common sense!

Kind Regards, John

 

[Taylortwocities]

How would adding a new Circuit on a Garage Consumer Unit (using an existing MCB on main CU) be treated?

It’s a new circuit.

In the unlikely event that you ever get to do an installation certificate you will find that when you install a consumer unit it will have its own certificate.
A certificate for the house consumer unit, another one for the garage, etc.
So, as you add circuits they (by definition) they are new circuits. Each with their own characteristics, each needing testing and therefore, to be street legal, needing notification to LABC.

EDIT
and after reading the post by @JohnW2
You seem to have a tame electrician who appears to be willing to sign his reputation away by saying that your work is his.
Probably better if you ask him/her the answer to this question, and any future queries?

 

[JohnW2]

How would adding a new Circuit on a Garage Consumer Unit (using an existing MCB on main CU) be treated?

Good question, and another situation in which 'the rules' (and/or some people's interpretation of the rules0 are not necessarily consistent either with easch other or with common sense - so you will probbably see a wide range of view expressed!

Some will argue that id the garage CU were supplied directly from the meter via a switch-fuse, then that CU would not be any different from any other CU, such that adding any 'new final circuit' to that CU would be notifiable That being the case, they might then go on to argue that feeding the garage CU from and MCB in the house CU is no different, so the same should apply.

Others (probably including myself!) will argue that, in many cases, the 'new wiring' in the garage could be achieved without a CU of any sort being there (e.g. adding a lighting circuit, or '13A sockets circuit' supplied by an FCU fed from the incoming supply, or even a sockets circuit fed directly from the incoming supply). They would then probably suggest that, since those 'alternative methods' of supplying the new loads would not be regarded (by most people!) as 'creating a new circuit' (hence notifiable), that should remain the case if it was done within an enclosure which happened to be called a "CU".

So, not 'black and white'. I know my personal view, hence what I would do myself (with a reasonably clear conscience) - but that's just me, and others have to decide for themselves. Unfortunately, unless one finds a particularly sensible one, "asking a BCO" is not usually an answer, since they will more often than not err in the direction of saying that things are notifiable!

Kind Regards, John

 

[ericmark]

Circuit. An assembly of electrical equipment supplied from the same origin and protected against overcurrent by the same protective device(s).

So question is New.

So we have a circuit formed by the DNO fuse, by the RCD, by the MCB, by any 13 amp fuse. And we get manufactures like Worcester Bosch who use other words like supply. Which all we have is Supplier (see Distributor). and for that:-
"Distribution circuit. A circuit supplying a distribution board or switchgear.
A distribution circuit may also connect the origin of an installation to an outlying building or separate installation,
when it is sometimes called a sub-main.
Distributor. A person who distributes electricity to consumers using electrical lines and equipment that he/she owns or operates."

So we have final circuits, and distribution circuits, so supply to garage is a distribution circuit and supply to sockets is a final circuit. But if you have a final circuit, then clearly there can be no other circuits after that point, so no circuits can come from a ring final, it is not an electrical thing, we are looking at the English.

So if not considered as a new circuit when used on a ring final, then can hardly be a new circuit when taken from a radial or spur either.

"Distribution board. An assembly containing switching or protective devices (e.g. fuses, circuit-breakers, residual
current operated devices) associated with one or more outgoing circuits fed from one or more incoming circuits,
together with terminals for the neutral and circuit protective conductors. It may also include signalling and other
control devices. Means of isolation may be included in the board or may be provided separately."

So any device with a single fuse, is not devices, it is a device. But
"Consumer unit (may also be known as a consumer control unit or electricity control unit). A particular type of
distribution board comprising a type-tested co-ordinated assembly for the control and distribution of electrical
energy, principally in domestic premises, incorporating manual means of double-pole isolation on the incoming
circuit(s) and an assembly of one or more fuses, circuit-breakers, residual current operated devices or signalling and other devices proven during the type-test of the assembly as suitable for such use."

Here is seems one fuse is a consumer unit, but one minute is says circuit(s) the next fuses not fuse(s), so may be we should look at the likely why, not the English.

So in many homes the Consumer Unit is the only device which can isolate the supply, in a perfect world we would have an isolator before the consumer unit (CU) so we could work on it dead, but in the real world, often the isolator does not exist, even where there are two CU's and we should have a single point of isolation, the isolator is missing, we have a supply to the off peak and supply to standard CU where only way to isolate is in the CU, in spite of HSE saying the supply should be isolated else where. Remember pulling the DNO fuse does not isolate as neutral still connected.

So it makes sense to say non trained personal should not work in a box where the supply can't be isolated, if we accept that as being the reason why we have new circuit rule, then no real problem working on a garage CU, however then it would say working in a CU as it does with bathrooms, even if not a new circuit.

So using English or Common sense we can only guess on the reason for the rule.

So next is court cases, the case law, well loads of court cases where people have said they were scheme members but were not, and where sub-standard work has been completed, but not simply that the work was not notified, there has always been some other problem.

So what is far more important is that the work is done to the standard laid out in BS 7671, if you have the test equipment and have used it, completing the installation certificate, with real figures not some fudged up results, one would be very unlikely to end up in court as a result, and even if you did, producing the installation certificate shows you exercised a duty of care.

As as to Part P, is it a law or a regulation? It is made very clear BS 7671 is not law, but can be used in a court of law, we know Part P came out to stop kitchen fitters, plumbers, builders and the like doing their own electrics to a sub standard quality, so following the rule book, the heating engineer can't wire up a new boiler without telling the LABC. And yes in my parents house, the gas safe, well back then likely Corgi guy fitted the central heating, and plugged it in, then next day electrician came and swapped the socket for a FCU and tested it all.

Remember this was a kitchen in Wales.

I know in Higher Kinnerton an electrician did some work, and did not supply the compliance certificate, as he did not realise it was in Wales, Lower Kinnerton is in England. The owner should know who he pays rates to, but tradesmen how are they to keep track. And it is getting a little petty saying some one can drink in one bar of a pub but not in the other one, where the Pub is on the boarder.

Same problem with Chester football club, car park in England, ground in Wales.

 

[Taylortwocities]

TL;DR
Sorry, Eric.