Does this setup contravene any regs or is it ok?

[Ian1981]

Well an FCU contains an OCPD (Fuse).
If I use an FCU to spur off from a circuit, does the fact that there is an OCPD at the origin of the spur, make the spur a separate circuit?

Where does the supply originate from?
The circuits primary OCPD.
Why twist things and be argumentative as per?

 

[Deleted member 26818]

Why twist things and be argumentative as per?

It’s what I do.

 

[Deleted member 26818]

Sometimes, it actually makes people think.

 

[Ian1981]

It’s what I do.

Haha.
Yes you always provoke a response I’ll give you that.

 

[MFS Electrical]

Ok where’s the OCPD at the origin of an installation?

That depends on how far back to “origin” you want to go? The MCB is an OCPD if it’s an origin of a final CCT. The bs1361 or 88-3 fuse is An OCPD if it’s the origin of a particular installation. The substation fuse, the grids fusing all the way back to the OCPD at the generator...

 

[MFS Electrical]

deleted

 

[Deleted member 26818]

That depends on how far back to “origin” you want to go? The MCB is an OCPD if it’s an origin of a final CCT. The bs1361 or 88-3 fuse is An OCPD if it’s the origin of a particular installation. The substation fuse, the grids fusing all the way back to the OCPD at the generator...

The distribution network is outside of the scope of BS7671.
As the discussion is in relation to an Assessor stating something does not comply with BS7671, I was thinking of the origin as per BS7671.

 

[MFS Electrical]

The distribution network is outside of the scope of BS7671.
As the discussion is in relation to an Assessor stating something does not comply with BS7671, I was thinking of the origin as per BS7671.

That’s why I stuck origin in quotation marks in just playing devils advocate sarcastically I may add

 

[Silly Sausage]

Well an FCU contains an OCPD (Fuse).
If I use an FCU to spur off from a circuit, does the fact that there is an OCPD at the origin of the spur, make the spur a separate circuit?

That'll be a sub-circuit

 

[markythesparky]

I'm also interested in why markysparky disagreed with sparkychick's post re lollipop circuits.

Because, as Spin helpfully points out, details on how a circuit is formed is in appendix 15. And as we seem to be so intent on dissecting the regs to the nth degree, there is nothing at all that looks remotely like a ‘lollipop’ circuits in app15. Therefore, if it is not in the regulations of how a circuit should be wired, it is not compliant.

 

[markythesparky]

An OCPD cannot be the origin of a circuit, because BS7671 allows OCPDs to be omitted and also allows them to be positioned along the run of a conductor.

Which is exactly why my view is that the origin is the cable and where it connects to the OCPD.

 

[DPG]

The regs cannot possibly show every possible circuit. I presume you would class any lollipop ring you come across as unsatisfactory then?

 

[SparkyChick]

The Appendix 15 argument.

Appending 15 is informative only, it doesn't matter how many times people claim it is a regulation, it isn't, it's there in black and white (INFORMATIVE).

The opening text reads "This appendix sets out options for the design of ring and radial final circuits for household and similar premises in accordance with Regulation 433.1"

Options... it is not the exhaustive list of possibilities that comply with 433.1, if it were some of what we do everyday would be non-compliant (like a 20A DP switch feeding a single socket for an appliance wired in 2.5/1.5mm cable - complies with 433.1.204 but isn't on the diagram in appendix 15).

For a ring circuit to comply with the regulations, it must comply with 433.1.204 which defines the acceptable topology of a ring final circuit purely in terms of cable loading. Thus providing the cables are not overloaded in accordance with 433.1.204, a lollipop or ring final circuit will comply.

 

[markythesparky]

The regs cannot possibly show every possible circuit. I presume you would class any lollipop ring you come across as unsatisfactory then?

If course! A C3 if I were doing an EICR.

And how can it be a lollipop and also a ring? What would you put under the continuity tests in an EIC and also if the ‘stick’ end is of a larger size what size cable do you put in the EIC?

 

[markythesparky]

The regs cannot possibly show every possible circuit. I presume you would class any lollipop ring you come across as unsatisfactory then?

So you make your own up!

 

[SparkyChick]

If course! A C3 if I were doing an EICR.

And how can it be a lollipop and also a ring? What would you put under the continuity tests in an EIC?

Maybe the continuity of the conductors of the ring portion???

 

[markythesparky]

The Appendix 15 argument.

Appending 15 is informative only, it doesn't matter how many times people claim it is a regulation, it isn't, it's there in black and white (INFORMATIVE).

All the appendixes are informative with the exception of the appendix 1.

The opening text reads "This appendix sets out options for the design of ring and radial final circuits for household and similar premises in accordance with Regulation 433.1"

It sets out the ‘options’ by indicating what can be done and what is acceptable.

Options... it is not the exhaustive list of possibilities that comply with 433.1, if it were some of what we do everyday would be non-compliant (like a 20A DP switch feeding a single socket for an appliance wired in 2.5/1.5mm cable - complies with 433.1.204 but isn't on the diagram in appendix 15).

Where does it say that it’s not exhaustive?

For a ring circuit to comply with the regulations, it must comply with 433.1.204 which defines the acceptable topology of a ring final circuit purely in terms of cable loading. Thus providing the cables are not overloaded in accordance with 433.1.204, a lollipop or ring final circuit will comply.

I’ve said all through this thread ‘loads accepted’ or ‘loads considered’. Lets drop this part as I have accepted this. My argument is not about this, only the make up of a circuit and where it starts.

I have said on numerous occasions that two or more circuits that are lumped together in a protective device is not necessarily electrically unsafe, but just that it doesn’t comply.

 

[Deleted member 26818]

Yes Appendix 15 is informative.
It provides us with information.
It’s not the be all and end all, but there is no logical reason why the information provided should be ignored.
(Except of course when it states a Radial starts and finishes at the DB.)

 

[markythesparky]

Appending 15 is informative only, it doesn't matter how many times people claim it is a regulation, it isn't, it's there in black and white (INFORMATIVE).

All the appendixes are INFORMATIVE with the exception of app1.

The opening text reads "This appendix sets out options for the design of ring and radial final circuits for household and similar premises in accordance with Regulation 433.1"

It sets out the 'options' (something that may be chosen) of how to wire a type of circuit. It does not give 'examples' (one of a number of things or a part of something, an instance serving for illustration). If it could be wired like a lollipop it would have a diagrammatical representation of this too!

Options... it is not the exhaustive list of possibilities that comply with 433.1,

Where does it say that?

 

[DPG]

The regs can't possibly show every possible wiring configuration. And they don't need to - a competent electrician does not need to follow a guide covering every option. wiring installations can still comply with the regs even if they aren't specifically drawn in the book!

 

[SparkyChick]

Where does it say that... it doesn't, but if you take a step back and look at what you're saying I think you might see your talking nonsense because you're saying that the only possibilities for complying with the regulations when constructing a ring final circuit are shown in appendix 15.

If so, explain to me how the example I gave (a 20A DP switch on a ring final supplying a socket outlet in 2.5/1.5mm cable) doesn't comply with the regulations, and I want actual regulation numbers.

If the only answer you can give me is that it's not shown in appendix 15, then you should only ever use double socket outlets on the main ring because that's how appendix 15 shows it... you should never have more than two double socket outlets after a fused spur because that's how appendix 15 shows it.... complete and utter nonsense.

As for the whole two circuits into one OCPD doesn't comply... I think you're wrong, you're not going to change my mind so we'll have to agree to disagree on that.

 

[markythesparky]

If so, explain to me how the example I gave (a 20A DP switch on a ring final supplying a socket outlet in 2.5/1.5mm cable) doesn't comply with the regulations, and I want actual regulation numbers.

I have never said that it doesn't and as such I cannot give reg numbers.

you should never have more than two double socket outlets after a fused spur because that's how appendix 15 shows it.... complete and utter nonsense.

App15 states 'the number of socket-outlets supplied from a fused connection unit is dependant upon the load characteristics, having taken diversity into account'. The regs therefore account for more than one socket after a spur.

you are trying to pin the argument down to individual parts of the circuit and my point has always been the proper way the whole circuit is wired and what is acceptable.

This has been a very interesting thread, more so because there has been no outcome. This will run and run i'm sure.

I would stake my pliers on it that the vast majority of inspectors from all schemes, will have the same view as the Stroma man. (And me).

 

[SparkyChick]

I would stake my pliers on it that the vast majority of inspectors from all schemes, will have the same view as the Stroma man. (And me).

I'll add it to the list of questions I have for my inspector, see what he says

And we'll have to agree to disagree.... pint? My round

 

[markythesparky]

I'll add it to the list of questions I have for my inspector, see what he says

And we'll have to agree to disagree.... pint? My round

Yep. Next time i'm in Wales I'll take you up on that.

 

[Zdb]

Brilliant thread!

I agree that it is NOT unsafe (if everything has been taken into consideration). If so it should comply with the regulations. IMO and many others, it's no different than having one cable in the OCPD going to a junction box supplying the two (technically one) circuits.

Having said that I also agree that it is bad practice and should only be done as a last resort.

I have actually had to do this myself on ONE occasion. I needed a way for my new circuit and there was no way the client was going to pay for a new DB. Luckily one of the circuits only had 6x LED GU10 spots on it in the sales room so I just added it to the other sales room lighting circuit which had 600x600 LED panels on it. All loading, switching etc were taken into consideration and I measured the maximum Zs which was fine.

It definitely wasn't my best job but neither was it unsafe. If the circuit had been designed today (with LEDs) they would have been on the same circuit anyway. It was just an old building which was obviously designed when lighting loads were much higher powered.


*awaits loads of abuse*

 

[oracle]

Would you not consider this as an extension or addition?

 

[oracle]

You can pick up four spaces by replacing the BS 61008 RCDs and using a mix of breakers and RCBO's as required.

Now leave my granny alone, I love her and Catherine Tate studied her for the portrayal of Nan in the series. She had a mouth that made truck drivers blush.

 

[markythesparky]

I thought I’d put my input into this thread to rest but I had ten minutes to spare today and this was still bugging me. So I took the opportunity to call the NICEIC technical helpline about it. I have been resurrected!

Their view is that the regulation, although short on specific detail, as a re a lot of the regulations (as it is simetimes very hard to express the intended rule in writing), does in fact intend that each circuit should be connected to only one OCPD. In view of ‘what is classed as a circuit, I specifically asked about lumping circuits together with the view that they both become one circuit, and the view was that they don’t. The circuit is defined as per the wiring was intended and it should comply with BS7671. They would class this as a non compliance.

I asked, if in the event that I found this whilst doing an EICR, would I flag it and if so what would I flag it as. The view was that it should be recorded as a C3 for definite or a C2 if there was a danger of overload or other problems.

This is the NICEIC technical helpline’s view at the time of calling and there are of course other schemes, none of which are necessarily more competent than the NIC or less. (Thought I’d throw that in for balance).

But in the meantime........


I’m am of course, as always, ready to be humbled!

 

[SparkyChick]

So, if I have an MCB in the CU (above the front door) that is currently supplying the downstairs lighting circuit and the client would like an exterior light by the front door. There are no spare ways in the board.

In this scenario you're saying you can't take a supply from the downstairs lighting MCB without contravening the regs?

Likewise, customer wants a double socket in his garage. CU is in there.

In this scenario you're saying you can't take a spur from the origin of the ring final supplying the downstairs socket circuit without contravening the regs?

If the answer is yes to either of those, it's laughably stupid I'm afraid and is a means by which the NICEIC are encouraging their members to rip off their clients. Sorry, but there is no other way to put it, it's a money making sham sanctioned by an organisation that is supposed to be protecting the clients of it's members. Absolutely laughable and a down right disgrace.

Did they perchance specify which regulations you would be contravening by indulging in such a travesty of wiring?

 

[markythesparky]

The Reg is 314.4.

You can run a spur from the OCPD from a ring and comply as it is specifically allowed in BS7671.

You cannot comply with BS7671 by bunching circuits such as lighting or radials in the same OCPD. It is non compliant.

And just to throw a rather large spanner in the works, the regulations also state that you are allowed deviations from the regs if you can prove that they are electrically as safe as the regs require them to be. This is what the deviations box is for in the EIC. The regs are of course non statutory so there is scope to adapt. It would still be a non compliance but under the regs it is allowed as long as you list it as a non compliance and justify your reasoning for doing it.