Extending Cooker Feed - Notifiable?

[ban-all-sheds]

There is room.

The question though is whether there is enough room in the concept of professionalism to allow someone who claims to be one to do something which to the best of his knowledge and belief does not comply.

 

[dhutch]

Basically as I see it then there are two options:

Ideal:
- 60amp Switch Fuse from incoming feed
- New 10mm T+E across house
- 10mm SWA down garden
- Garage CU, RCD,
- 32amp mcb, ring main
- 16amp mcb, 16amp outlet
- 6amp mcb, lighting circuit

Minimum
- 32 amp mcb from main CU
- Existing 4mm cooker feed over house
- Existing DP isolation switch in kitchen
- 4mm SWA down garden to garage
- Junction box, 4mm radial to sockets
- 5amp FCU to lighting circuit
- Possable use of emergancy light to provide ilumination incase of power failure.

Technically, if the cooker feed wasnt in the kitchen, and I just put single socket in the garage, it wouldnt be notifiable, but as it is in the kitchen it is there for notifiable and should be installed by someone qualified.


Daniel

 

[JohnW2]

Basically as I see it then there are two options:

Yep, I think I would almost completely agree with that. Even with your 'ideal' option, you might want to consider radial(s), rather than a ring circuit, for the power - either a 4mm² 32A radial or two 2.5mm² 20A radials.

Technically, if the cooker feed wasnt in the kitchen, and I just put single socket in the garage, it wouldnt be notifiable, but as it is in the kitchen it is there for notifiable and should be installed by someone qualified.

As you've seen, that's contentious. BAS feels strongly that it would not be notifiable, even with the connection between cooker and SWA was in a kitchen. I am a little less certain of the intended interpretation of Schedule 4 of the building regs but have been bold enough to say that, even if it technically were notifiable, I would regard that as so silly that I would be very tempted to 'break the law'!

Kind Regards, John

 

[ban-all-sheds]

as it is in the kitchen it is there for notifiable and should be installed by someone qualified.

Notifiable or not, it should be installed by someone qualified-with-a-small-q, i.e. competent, to install and test it properly.

 

[JohnW2]

Notifiable or not, it should be installed by someone qualified-with-a-small-q, i.e. competent, to install and test it properly.

No argument with that. That could/does, of course, even exclude at least some people who call themselves 'electricians'.

Kind Regards, John

 

[scousespark]

Quibble away, and then deal with the fact that your quibbling means that there is no longer any non-notifiable work where a junction box is used as there is no mention of them in Schedule 4.

It's not the existance of JB which is the issue - and I disagree with what you say, since neither is there any mention of cable in relation to (non-notifiable) extensions to add sockets, FCUs, lights and switches. I will therefore happily interpret the Schedule as meaning that things like cable and JBs are implicitly allowed as part of these works that can be done without notification.

The issue is about the location of the JB in a kitchen - but, as you know, I'm not really one to quibble about this. True, I am not completely sure of the intention of Schedule 4 as regards this - but, as I've said, even if the intention of the law is to require such a thing to be notified, then that is a law which I would happily and comfortably break.

Kind Regards, John

You think this law is silly, so advise that it's one to ignore. If the OP decides to run the circuit from the CU, is that also a small enough job to ignore?

 

[scousespark]

Ive done some reading on discrimination. What would you usually do to add some of that then? Short of up'ing the cable or seriously derating the final circuits I dont see how you would? Can you get a slow-blow fuse to protect the cable.

In your case, the simplest solution is not to 'add in discrimination' but, rather to reduce the number of overcurrent protective devices (OPDs - MCB/fuse) to one - so there are not two things to 'discriminate' between. An OPD is only there to protect the cable. Provided all cable is fat enough to be adequately protected by the OPD at the house CU, there is no need for any MCB/fuse anywhere else. If you want to run a 'sub-circuit' in smaller cable (e.g. for lighting), then you can take that off the main supply via a fused connection unit (FCU), with a fuse in that small enough to protect the size of cable concerned (say 3A or 5A). That should discriminate satisfactorily with, say, a 20A or 32A MCB in the CU.

Kind Regards, John

As I understand this, you suggest he runs a 10mm SWA cable directly to a socket, with an FCU somewhere along the run to feed the light. How do you connect the FCU and socket to the SWA?

 

[scousespark]

I see, so I would just have the MCB in the consumer unit, which would protect the cable and everything beyond it, with then a 5amp FCU to the lighting. Interesting.

Exactly. That's the usual 'simple' supply to a garage.
Kind Regards, John

You may have seen this, but it is not common for a detached garage.
It's a poor design.

 

[scousespark]

So if you where doing a 'perfect job' you would have a 60amp fuse at the CU, leading to 10mm csa cable, then the garage CU with you 32amp final circuit MCB/RCBO.

Yep, I suppose that's about it - but for the average person who wants just a socket or three and some lighting in a garage, to do that just to achieve discrimination could well be regarded as rather 'OTT'!

Kind Regards, John

There is no justification for a DIYER not working to the same standards as a professioinal. Where have you seen it stated that you can ignore discrimination if you are only supplying a couple of sockets?

 

[JohnW2]

You think this law is silly, so advise that it's one to ignore.

Firstly, I did not 'advise' - I merely stated what I personally would be comfortable to do - because I feel that I could put up a strong defence in terms of the 'spirit' (and hence my view of the intent) of Schedule 4 of the Building Regs.

However, BAS, for one, is totally convinced that 'the law' does not require notification of work which would otherwise be non-notifiable just because it involves a JB which happens to be in a kitchen. There's certainly a lot of common sense in that interpretation (which is why I feel I would have a strong defence), but I'm just not totally convinced that such is what the word of the law actually says - what is your view?

If the OP decides to run the circuit from the CU, is that also a small enough job to ignore?

If you're talking about running a 'new circuit' from the CU, that's utterly different, since there is no doubt that such would be notifiable - and no argument/defence that one could produce for not notifying. My view as to whether or not such a job should be notifiable is irrelevant (and I haven't stated it).

Kind Regards, John

 

[scousespark]

Ah well - one man's boring and less fun electrical design is another's professionalism and sense of responsibility and duty of care, I guess.

Maybe. Professionalism does not necessarily preclude (indeed, probably should include) realism, common sense and case-by-case risk assessments - and, in the case we're discussing, there is enough wiggle room in the wording of the regs to allow professionals to make some decisions on their own, rather than having to act as robotic followers of a cookbook - i.e. be proper professionals.

Kind Regards, John

The wiggle room about notifying is one thing. There is no wiggle room when it comes to the design. Spurring to run a 12 metre length of SWA and then connecting directly to the sockets and FCU would be poor design.

 

[scousespark]

didnt think you could put a ring on the end of a piece of cable like that anyway?

I can't see any electrical reason why not, provided that the cable up to the ring is of large enough CSA and (as discussed) protected by a 32A MCB - after all, that's no different from having a sub-main to a distant CU, from which a ring then originates. What one obviously can't do is, say, have a 2.5mm² ring connected back to the CU (and 32A MCB) via a single 2.5mm² cable. Having said that, I really don't see why Daniel needs a ring.

Kind Regards, John

You wouldn't run the feed to sub-main in 10mm cable and then carry this on the individual circuits.

 

[scousespark]

You think this law is silly, so advise that it's one to ignore.

Firstly, I did not 'advise' - I merely stated what I personally would be comfortable to do - because I feel that I could put up a strong defence in terms of the 'spirit' (and hence my view of the intent) of Schedule 4 of the Building Regs.

However, BAS, for one, is totally convinced that 'the law' does not require notification of work which would otherwise be non-notifiable just because it involves a JB which happens to be in a kitchen. There's certainly a lot of common sense in that interpretation (which is why I feel I would have a strong defence), but I'm just not totally convinced that such is what the word of the law actually says - what is your view?

If the OP decides to run the circuit from the CU, is that also a small enough job to ignore?

If you're talking about running a 'new circuit' from the CU, that's utterly different, since there is no doubt that such would be notifiable - and no argument/defence that one could produce for not notifying. My view as to whether or not such a job should be notifiable is irrelevant (and I haven't stated it).

Kind Regards, John

Not everybody asking for advice here would have the background knowledge to deternine whether it was safe to ignore the requirement to notify. I also think it's a silly law, but wouldn't print here that I'd ignore it (as this could be read as advice). It's a grey area, but the arbiter is the LABC (some would say it needs notifying and others would say not).

My point is that, assuming a job is notifiable there is no justification for ignoring it.

 

[JohnW2]

Exactly. That's the usual 'simple' supply to a garage.

You may have seen this, but it is not common for a detached garage. It's a poor design.

I obviously cannot argue with your experience, but I've seen it a lot. It's also what one commonly sees being advised here, with OPs often being quizzed as to why they feel they need a CU in a garage (rather than just a socket or two and an FCU for the lighting).

Kind Regards, John

 

[JohnW2]

There is no justification for a DIYER not working to the same standards as a professioinal.

No argument with that.

Where have you seen it stated that you can ignore discrimination if you are only supplying a couple of sockets?

Discrimination between what and what? Are you referring to the undesirability of having both power and lighting on the same OPD (which is not really 'discrimination') - as in the 'no CU in garage' approach? With that approach, there is obviously no discrimination issue. The (prbably 3A or5A) FCU fuse will (probably!) discrimate from the (32A) MCB in the house CU, and the garage sockets have no discrimination issue at all, since their only OPD is in the house.

Kind Regards, John