Ring spurred at origin?

[Andy78]

Sounds like a problem waiting to happen. I'd get an electrician in to do this for you properly.

 

[Spoon]

Sounds like a problem waiting to happen. I'd get an electrician in to do this for you properly.

what??? and spend money???? are you mad??

 

[Pete999]

This is somewhat unconventional and is clearly ad hoc, yes it should be on its own circuit as I have also suggested but the limitations of what can be added to this spur is clouded by the cable size, 4.0. Appendix 15 which is informative does not demonstrate the use of 4.0 cables/conductors.

Yes it does on a 32 or 30Amp Radial circuit
Wired in 4mm2
2oAmp Radial wired in 2.5mm2

 

[Pete E]

if the CU is in the garage anyway, why not split the tails with \Henley blocks and fit a "garage board". RCD + 2/3 MCBs. then a fault in the garage will not saffect the house CU andyou would have a spare way/s. a 4mm 32A radial for sockets, 6A MCB for lights.....

I assume that need to be notifiable under Part P?

 

[westward10]

Yes it does on a 32 or 30Amp Radial circuit
Wired in 4mm2
2oAmp Radial wired in 2.5mm2

I am talking ring final circuits. But yes you could consider this a 4.0 radial so I see no need for a fcu but circuit separation should be employed.

 

[Spoon]

I assume that need to be notifiable under Part P?

Yes mate.

 

[mattrgee]

Thanks all.

Tempted to leave it as is for the time being and not add any additional sockets. There's a bathroom renovation on the cards soon where there is an electric shower running from a dedicated circuit. Once that has been decommissioned I'll ask he electrician to create a dedicated circuit for the garage sockets.

 

[Pete E]

Yes mate.

View attachment 41350

I thought so...I think when work becomes notifiable, its probably cheaper and certainly less hassle to get a suitably qualified Spark in...

 

[westward10]

Adding/altering this existing circuit would not be notifiable.

 

[Pete E]

Adding/altering this existing circuit would not be notifiable.

I was referring to the option of fitting an additional CU for the garage etc that was mentioned earlier in the thread..

 

[westward10]

Okay with you now.

 

[Devonchris]

The more I read this thread the more confusing it becomes.

As far as I see it,

There is nothing wrong with a spur on a Rfc taken from the CU.
Its in the OSG 7.2.2 para 4.

The spur would normally be in 2.5mm2, but the fact that it's in 4mm2 is not a problem. (Might be a big garage, VD and all that)

If the socket is replaced with a FCU then there's no limit on how many sockets can be connected to the load side, as long as your happy with the 13 amp limitation.

As this is not a new circuit then it does not require Part P notification.

 

[Midwest]

I think most have an issue with the termination of 1 x 4mm & 2 x 2.5mm conductors in a singular mcb, and the possibility of the connection not being tight enough?

 

[Devonchris]

Fine, I can see that point. But isn't that down to whoever is doing the installation and not what is allowed and what isn't?

 

[mattrgee]

The spur would normally be in 2.5mm2, but the fact that it's in 4mm2 is not a problem. (Might be a big garage, VD and all that)

Is this because it's on a B32 MCB?

 

[Pete999]

Is this because it's on a B32 MCB?

It's a spur from a 2.5mm2 RFC albeit from the CU, no problem with that, why 4.0mm2 was used is a mystery, it makes no difference to what you can and can't add, a spur is a spur, one twin or single socket only fed directly from the RFC without a FCU involved. Nothing to do with the B32 Amp CB rules is rules is rules.

 

[westward10]

Where is this rule for a 4.0 spur.

 

[Pete999]

Where is this rule for a 4.0 spur.

Where is this rule for a 4.0 spur.

Not one as far as I am aware, Westy. I was just wondering why a 4.omm2 was used, just makes life dificult for the installer.

 

[westward10]

It is an ad hoc addition, no spare ways so whack it on the ring.

 

[Devonchris]

As pete said, there isn't a rule, but there's nothing preventing it. Cable sizing in the guides are the "minimum " requirements.

We don't know the cable size in the RFC that the spur is connected to. The op has never declared that. The whole thing could be in 4mm2. It's pure speculation on our part that's its 2.5mm2 because that's the norm.