Garage spurred off ring...

[Noob2013]

Hi all,

I have been practising my testing at my parents house as I'm still an apprentice.

Just a quick question. The garage, which is separate from the house has been spurred off the ring main with an SWA. The cable run is approximately 5 metres and is terminated in an isolator in the garage. The isolator then feeds a double socket and FCU for a light.

The ring is protected by an rcd.

Is this acceptable?

 

[jurrassic spark]

how is the SWA connected to the ring circuit!

 

[Noob2013]

I believe it's off of a socket

 

[telectrix]

i think what he meant was .... is the SWA properly glanded and the armour earthed. this is usually acheived by coming from the socket in T/E and connecting into the SWA in an adaptable box on the outside of the house wall.

 

[Noob2013]

Sorry misunderstood.

There are no signs of boxes or FCU and it is not fed from the socket nearest the cable entry. Therefore, I can only assume it has been put in a junction box under the floorboards. Not good!

The armoured is 3 core so has an earth and the earth loops are fine but I doubt the armoured itself is earthed.

What code would that be on a report?

 

[telectrix]

C2. if armour is not earthed.

 

[Tiny Spark]

Easy way to check if the armored is earthed, Do a R1 R2 test between the line and the armoring

 

[Noob2013]

Easy way to check if the armored is earthed, Do a R1 R2 test between the line and the armoring

Thanks, will do that.

Is it dangerous if its been spurred off the ring circuit in a junction box?

It's been like it since my parents moved in and have never had a problem. It is also protected by the RCCB at consumer unit.

 

[Tiny Spark]

It should be fused down really in case someone tries to extend the circuit in future or overload it.
We cant tell you if its safe or not but if its been done properly there will be nothing wrong with it although its not the way I would do it!

 

[Noob2013]

Ok thanks.

If its not earthed then I will put a properly gland on and earth the SWA.

It will then supply one Rcd socket and one spur for the light fitting.

 

[EastAnglian]

As you earlier stated that the ring from which it has been spured is RCD protected there is no need to install an RCD protected socket outlet in the garage (assuming that the installed RCD has an operating current of 30mA). Indeed, to do so will be non-compliant with BS7671 as there will be a lack of discrimination between the series-connected RCDs.

I would expect to see a 13A fused connection unit on such a spur at the feed end and for practical purposes I would always install a 2-pole isolation switch at the house end in case there is any need to take the external circuit out of service (best combined as a switched FCU).

Lighting in the garage should be via a 3A FCU.