ring with spurs

[Hawk]

How do you guys record a spur off a ring on a test certificate?

 

[Risteard]

The origin of a circuit is at the DB/CU as stated in Appendix 15.

It's hardly relevant quoting an Informative appendix which does not form part of BS 7671.

 

[Spoon]

To start with, I would mention the situation in the 'comments on the existing installation' section of the report.

The spur should be unswitched, with a 5A fuse also labeled for 5A fuse max. The as for the lighting circuit should then fall within the allowed As for fuse in spur.

Why label it? Does it say so in the regs? Only an idiot would put a bigger fuse in.
Shouldn't you then label every fused spare, like for extractor fans....

 

[Deleted member 26818]

It's hardly relevant quoting an Informative appendix which does not form part of BS 7671.

Don't know whether to do a number of lols, or perhaps a 'seriously?', just not too sure how to respond to something so obviously incorrect?
Of course the appedicies form part of BS7671, they provide reference, instruction and information to aid compliance with the requirements of the Regulations.
Why do you believe that quoting information is not relevant?
Are you advocating that the information should be ignored?
Is the reason why you advocate ignoring the information, because it does not agree with your viewpoint?

 

[davesparks]

To start with, I would mention the situation in the 'comments on the existing installation' section of the report.

The spur should be unswitched, with a 5A fuse also labeled for 5A fuse max. The as for the lighting circuit should then fall within the allowed As for fuse in spur.

Why should it be unswitched?

 

[davesparks]

The people who suggest that a fused spur from a circuit would be a separate circuit are incorrect.
The origin of a circuit is at the DB/CU as stated in Appendix 15.

But if you look in the definitions at the front of the book then you'll find it defines a circuit by the OCPD, not necessarily by being connected to a DB

I think this one is a bit of a grey area really.
If I'm wiring a circuit which is fed by an existing SFCU, like a replacement boiler for example, I will record the fuse in the SFCU on the minor works cert rather than whatever is feeding the SFCU as it would have no relevance to the work done.
However in the OP's scenario I wouldn't record it as a seperate circuit, however I would still inspect and test it.

 

[Deleted member 26818]

How is it a grey area?
It states quite clearly in BS7671 that the origin of a circuit is at the DB.
Is it just me, or do things become grey or open to interpretation, only when people want to swerve the Regs?

 

[davesparks]

How is it a grey area?
It states quite clearly in BS7671 that the origin of a circuit is at the DB.
Is it just me, or do things become grey or open to interpretation, only when people want to swerve the Regs?

I haven't got the book to hand at the moment, but I'm pretty sure the definition of a circuit is something along the lines of 'all conductors and equipment connected to a common OCPD' nothing to do with a DB
A circuit cannot be defined by being connected to a DB otherwise any circuit connected to a switch-fuse or fuse-switch, such as a submain, would then not be a circuit?

 

[Deleted member 26818]

Appendix 15 which provides information for the setting out of RFCs and Radials, states that a RFC starts and finishes at a DB, and that Radials start at a DB.
We also have the requirement in Regulation 314.4: In installations where there is more than 1 final circuit, to connect each final circuit to a separate way in a DB.
The problem with relying on Definitions, is that often things other than what is being defined, satisfy the definition.
According to the Definition of a circuit, an installation, is a circuit. As also is a fridge, or a TV.

 

[davesparks]

Appendix 15 is informative only, the definitions form part of the regulations.

So with regards to 314.4 would you say that a final circuit fed from a switchfuse is not a circuit?
For example a standard final circuit in a theatre would be feeding a 125A ceeform socket or 400A powerlock sockets, often fed via a switchfuse or fuse-switch, is this not a circuit as it's not fed via a DB?

 

[Deleted member 26818]

Yes it provides information relating to RFCs and Radials.
Yes the definitions form part of the Regulations. As such every time you plug something in, you must issue an EIC according to the Regulations.
Do I say that?
What I say is just because something satisfies a definition, it doesn't mean it is what is being defined.
Sounds like it's a circuit to me, as to whether it complies with BS7671, that's something else.

 

[Midwest]

It's hardly relevant quoting an Informative appendix which does not form part of BS 7671.

I'm with spinlondon on this. I understand that the appendices are informative and are not regulations themselves. But why do the do the authors put them in their book, if you are not act upon them or refer to them? Definition of appendices (Wikipedia); Generally, any text added to the end of a book or an article, containing information that is relevant to the main subject matter.

 

[Midwest]

BS7671 definition of circuit; An assembly of electrical equipment supplied from the same origin and protected against overcurrent by the same protective device(s). If the argument is which ocpd to record on a certificate for a FCU, then my understanding is that it has to be the ocpd in the DB. That ocpd protects the whole of the circuit, including the radial or ring final that is feeding the new FCU, without that the FCU doesn't function. When a ring final or radial is installed, the ocpd at the DB/CU is recorded on the cert', not the 1361 fuse in the plugtop.