Outside light cable zone query

[EddyP]

Before I plaster the new utility room/wc i'm considering running a cable for a light on the outside of the wall, as it's next to the patio, what are the rules regarding the zone here though, the cable will be RCD protected and less than 50mm in the wall, do I need to run it down the corner of the room only or is it ok to run it down the wall then through it into the back of the outside light?
Need to make sure everythings ok as the building inspector is coming Monday morning to check i've zoned everything ok.

Thanks

 

[electronicsuk]

You can only run inside the safe zones, so no, unless there is an accessory in line with the cable drop then you cannot run it down the wall unless within 150mm from the ceiling or a corner.

 

[seasickstevie]

If you're coming down vertically then through into the back of the fitting, then that would be in the safe-zone, regardless of distance from ceiling.

 

[333rocky333]

Depends if the wall is less than 100mm thick and how you interpret reg 522.6.6 (v)

 

[VanSolo]

Would it look ok to have a blank plate in the place where the cable is going through the wall? If this is ok you could fit a flush single box and a blank plate and this would give you your safe zone for your cable drop.

 

[seasickstevie]

Would it look ok to have a blank plate in the place where the cable is going through the wall? If this is ok you could fit a flush single box and a blank plate and this would give you your safe zone for your cable drop.

What would be the point?
There's a light on the other side of the wall.
That puts it in the SZ.

 

[VanSolo]

I assumed an external wall would be over 100mm thick.

 

[seasickstevie]

I'm obviously missing something.

What's the relevance of whether the wall is 100mm thick or not, bearing in mind that the cable will be in the safe-zone?

 

[RF Lighting]

The safe zone only extends to the other side of the wall if the wall is <100mm thick.

If the wall is >100mm thick there is NO safe zone on the other side.

 

[seasickstevie]

Ah! That clears that up then.

This is something that doesn't seem to get mentioned much. At least I've not heard it mentioned as far as I can remember.

Bearing in mind pretty much all masonry walls are >100mm you can take it that only internal stud walls are going to mirror the SZ on the opposite side.

I take VanSolo's point of the blank plate in that case

 

[333rocky333]

Depends if the wall is less than 100mm thick and how you interpret reg 522.6.6 (v)

It is in the regs book, but at the end of a long and important page which affects nearly every electrical job now, so easily missed.