Cable zones.

[pete01]

Can you create a zone with a different circuit?

E.g. use a socket circuit zone to protect lighting circuit cable feeding an outside light?

If not what reg I can't seem to find one or any info on it?

 

[Murdochcat]

Yes. As long as the cable runs either horizontally or vertically then the safe zone can be used by any cable

 

[pete01]

I was sure (ish) the zone had to be the same circuit....I assumed incase the other circuit was removed....

 

[JohnW2]

Can you create a zone with a different circuit? E.g. use a socket circuit zone to protect lighting circuit cable feeding an outside light? If not what reg I can't seem to find one or any info on it?

I don't think so - unless you somehow connect/terminate/join the cable from the 'other circuit' in the backbox of the accessory which creates the 'zone'.

We've discussed this quite often, and what I've just suggested makes sense - since it would otherwise be possible for someone to render your 'other circuit' cable 'out-of-zones' by removing the accessory which had been creating the zone you had used.

 

[JohnW2]

I was sure (ish) the zone had to be the same circuit....I assumed incase the other circuit was removed....

Yes, I believe that is almost correct (and Murdo wrong), and for the reason you state. However, read what I've just written. I think that if, say, you cut your 'other circuit cable' and joined it in a connector in the box of the accessory creating the zone, then you may well be OK.

 

[pete01]

I don't think so - unless you somehow connect/terminate/join the cable from the 'other circuit' in the backbox of the accessory which creates the 'zone'.

We've discussed this quite often, and what I've just suggested makes sense - since it would otherwise be possible for someone to render your 'other circuit' cable 'out-of-zones' by removing the accessory which had been creating the zone you had used.

Is there a reg number? I cant find anything...

 

[JohnW2]

Is there a reg number? I cant find anything...

(with my emboldening) .....

522.6.202 A cable installed in a wall or partition at a depth of less than 50 mm from a surface of the wall or
partition shall:
(i) be installed in a zone within 150 mm from the top of the wall or partition or within 150 mm of an angle formed
by two adjoining walls or partitions. Where the cable is connected to a point, accessory or switchgear on any
surface of the wall or partition, the cable may be installed in a zone either horizontally or vertically, to the
point, accessory or switchgear. ............................

 

[JohnW2]

Is there a reg number? I cant find anything...

I should perhaps have added - since, as far as I am aware, there is only one reg which says anything about 'zones' for concealed cables, I'm a little surprised that you had trouble finding it

 

[pete01]

I should perhaps have added - since, as far as I am aware, there is only one reg which says anything about 'zones' for concealed cables, I'm a little surprised that you had trouble finding it

Thanks, yes I should have tried harder

 

[Murdochcat]

Yes, I believe that is almost correct (and Murdo wrong), and for the reason you state. However, read what I've just written. I think that if, say, you cut your 'other circuit cable' and joined it in a connector in the box of the accessory creating the zone, then you may well be OK.

Well, I’ve come across countless installs like I described. So I’m not the only one doing this.

At the end of the day I see no problem with what I originally wrote

And bear in mind that if the cable runs down the top 6 inches off the wall only that entire zone is a safe zone

 

[JohnW2]

Well, I’ve come across countless installs like I described.

I don't doubt that, and I'm sure the same is true of many others.

So I’m not the only one doing this.

I'm sure you're not. Lots of people are doing all sorts of non-compliant things.

At the end of the day I see no problem with what I originally wrote

Well, the only 'problem' I see is that what you wrote would be non-compliant with BS7671, but a good few people might not 'have a problem' with that!

And bear in mind that if the cable runs down the top 6 inches off the wall only that entire zone is a safe zone

I don't really understand what you are trying to say or what relevance it has to what was being discussed.

 

[securespark]

And bear in mind that if the cable runs down the top 6 inches off the wall only that entire zone is a safe zone

Can you explain that in a diagram, please?

 

[pete01]

Can you explain that in a diagram, please?

I think he means the 150mm around the top of the wall (6 inch) safe zone

 

[JohnW2]

I think he means the 150mm around the top of the wall (6 inch) safe zone

We know that is the case, but he gave the impression that he was suggesting something a bit more complicated than that, didn't he?

 

[pete01]

We know that is the case, but he gave the impression that he was suggesting something a bit more complicated than that, didn't he?

Not sure, dont think so.