Found a spur on a spur (I think) in my garage

[littlespark]

Ok… so does the garage spur from behind the tv pass through a switch fuse? This would limit the load to the 13A fuse, and a “spur from a spur” wouldn’t apply.

I hope they glanded the house end of the SWA properly.

For a new new build, I would have thought a separate rfc for just kitchen sockets and possibly dedicated radial circuits for high power appliances such as washing machine.

Also a full RCBO board would be preferable, not dual RCD… (although still ok with regs) and should have an SPD fitted unless you specifically said not to.

 

[Julie.]

OK, two answers to the spur from a spur.

Firstly, the regulation 433.1.1 basically says that the cables must be protected against overload (too much current due to loading, not a fault).

If the spur is fused at the take off point, this means it's protected, so no issue, if it's just one socket outlet, again OK as there are fuses in the plugs limiting the overall current.

If however you have multiple outlets (2x13A socket + 13A fcu) this could exceed the rating of the swa (don't know size, so can't be sure) in this case it is actually prohibited, not because it's a spur from spur, but because the cable could be overloaded due to insufficient protection.

In saying that, in practical terms, swa can run hotter than pvc, so is unlikely to be an issue, especially as the fcu is only feeding a lighting circuit.

So as it is, providing it's been terminated correctly etc, it is unlikely to be a problem.

Extending it however wouldn't be possible without rework, so it does have limited adaptability in the future.

So depending upon the swa size, it could be compliant, or non-compliant but unlikely to be an issue in either case.

 

[timhoward]

So depending upon the swa size, it could be compliant, or non-compliant but unlikely to be an issue in either case.

My assumption from the photo is that it’s 1.0 or 1.5 sq mm connected to the load terminals of the FCU so ‘probably’ the SWA and T&E are 2.5 sq mm. Photo’s can be deceptive though!
Worst case tabulated CCC value would be 32A if this guess is correct.

 

[Julie.]

My assumption from the photo is that it’s 1.0 or 1.5 sq mm connected to the load terminals of the FCU so ‘probably’ the SWA and T&E are 2.5 sq mm. Photo’s can be deceptive though!
Worst case tabulated CCC value would be 32A if this guess is correct.

Yeah, that was my thought, hence if it did come direct it wouldn't be a problem either, but difficult to confirm from the photo.

 

[prosist]

OK, two answers to the spur from a spur.

Firstly, the regulation 433.1.1 basically says that the cables must be protected against overload (too much current due to loading, not a fault).

If the spur is fused at the take off point, this means it's protected, so no issue, if it's just one socket outlet, again OK as there are fuses in the plugs limiting the overall current.

If however you have multiple outlets (2x13A socket + 13A fcu) this could exceed the rating of the swa (don't know size, so can't be sure) in this case it is actually prohibited, not because it's a spur from spur, but because the cable could be overloaded due to insufficient protection.

In saying that, in practical terms, swa can run hotter than pvc, so is unlikely to be an issue, especially as the fcu is only feeding a lighting circuit.

So as it is, providing it's been terminated correctly etc, it is unlikely to be a problem.

Extending it however wouldn't be possible without rework, so it does have limited adaptability in the future.

So depending upon the swa size, it could be compliant, or non-compliant but unlikely to be an issue in either case.

Thank you very much for your clear answer.


I went through all this because I had a plan of creating a spur there (before realising it was a spur itself) to install a floodlight to the outside of the garage.
What could I do if I wanted to add a 50W light from this circuit? (please let me know if I should make a new post in DIY forum instead)

 

[default]

Ok… so does the garage spur from behind the tv pass through a switch fuse? This would limit the load to the 13A fuse, and a “spur from a spur” wouldn’t apply.

I hope they glanded the house end of the SWA properly.

For a new new build, I would have thought a separate rfc for just kitchen sockets and possibly dedicated radial circuits for high power appliances such as washing machine.

Also a full RCBO board would be preferable, not dual RCD… (although still ok with regs) and should have an SPD fitted unless you specifically said not to.

The new rules on SPDs only came into effect this year. If the plans for the development where passed before this and the work was started the new regs do not apply.

 

[prosist]

Sorry for being such a newbie. I went to look in where it goes out of the ring and there is a fuse there. So it is a fused spur as soon as it leaves the socket and then there is a second 3A fuse for the light.
Thank you all

 

[littlespark]

Sorry for being such a newbie. I went to look in where it goes out of the ring and there is a fuse there. So it is a fused spur as soon as it leaves the socket and then there is a second 3A fuse for the light.
Thank you all

So as I said, it’s a fused spur, so it’s protected by the 13A

Score 1 to the LS

 

[Spoon]

I went through all this because I had a plan of creating a spur there (before realising it was a spur itself) to install a floodlight to the outside of the garage.
What could I do if I wanted to add a 50W light from this circuit? (please let me know if I should make a new post in DIY forum instead)

Hi mate. Just add it to the 3A circuit in your garage.