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Topic Title: cable routing
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Created On: 12 November 2012 03:22 PM
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 12 November 2012 03:22 PM
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krishanc

Posts: 142
Joined: 24 September 2003

Hi Came across a small issue on a domestic PIR. 2x light units fed from switch. cables in conduit just above light fitting for full length of run to final light fitting. But just above the first light fitting where cables are run down into light fitting from conduit about 1cm of exposed wires including sleeved earths is visable. This is due the fact the wires coming into light fitting via a cut in the metal fitting at the top of it and its not right against the wall. The job is as neat as it can be actually. The only way it could be perfect is if the cables were within wall and came into fitting via hole of the light fitting. Is this a failure on the regs? The 1cm exposed wires is not visable, only if you climb a ladder to the top of the light fitting. KC
 12 November 2012 04:04 PM
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AJJewsbury

Posts: 10964
Joined: 13 August 2003

I'm not sure I'm picturing this right.

Is this surface conduit? (in a domestic??)

Usual solution is to put a box on the bottom of the conduit and mount the wall light on top of (i.e. in front of) that (sounds odd, but looks OKish, especially if not normally viewed from the side).

Alternatively could sheathed cables be used instead of singles (so electrically speaking it wouldn't matter if they were exposed).

521.10.1 doesn't seem to have an exception for "out of sight"...

Unsheathed wires and site-made holes in metal fittings doesn't sound ideal to me...

- Andy.
 12 November 2012 05:54 PM
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krishanc

Posts: 142
Joined: 24 September 2003

Originally posted by: AJJewsbury

I'm not sure I'm picturing this right.



Is this surface conduit? (in a domestic??)

Yes, conduit screwed to brickwork (conservatory)


Usual solution is to put a box on the bottom of the conduit and mount the wall light on top of (i.e. in front of) that (sounds odd, but looks OKish, especially if not normally viewed from the side).

The only thing with this is the wall light will be away from the wall and I would agree with home owner that it would look odd to say the least.


Alternatively could sheathed cables be used instead of singles (so electrically speaking it wouldn't matter if they were exposed).

No, not possible, the whole place would look bad.

521.10.1 doesn't seem to have an exception for "out of sight"...

yes, but remember the regs are a guide, in reality this is no danger here its just not 100% great, either its done as you say or channelled out in the wall. The question is, is it something I should state as a deviation and if so what code would I use, C4?

Unsheathed wires and site-made holes in metal fittings doesn't sound ideal to me...



- Andy.


 13 November 2012 07:36 AM
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zeeper

Posts: 1378
Joined: 11 July 2008

yes, but remember the regs are a guide


By complying with the Britsh Standard 7671:2008 amended 2011, it will help you comply with statutory regulation, which is law.

I should state as a deviation and if so what code would I use, C4?


Maybe use one that is relevant to the current BS7671.

C1 Danger present
C2 Potentially Dangerous
C3 Improvement recommented
 13 November 2012 09:15 AM
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AJJewsbury

Posts: 10964
Joined: 13 August 2003

Alternatively could sheathed cables be used instead of singles (so electrically speaking it wouldn't matter if they were exposed).

No, not possible, the whole place would look bad.

Sorry, I wasn't clear - I meant sheathed cables inside the conduit.

- Andy.
 13 November 2012 10:38 AM
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AJJewsbury

Posts: 10964
Joined: 13 August 2003

The 1cm exposed wires is not visable, only if you climb a ladder to the top of the light fitting

But people do climb on ladders - whether for dusting or decorating or changing a lamp. If you're relying on basic insulation only, it's not really compliant.
- Andy.
 13 November 2012 11:38 AM
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krishanc

Posts: 142
Joined: 24 September 2003

I knew this would the real deal anyway, I was just hoping I did not have to fail the install on the grounds of that 1cm exposure. since its an external wall, ie., no plaster, the only solution is as you say, insert a wood block around the conduit and bring in the cables via the light fitting intended method through the hole at the back plate and wood block, give the style of light fitting it would look really odd, will have to ask owner to look at changing the light fitting to one that wont look so odd. cheers KC
 13 November 2012 07:32 PM
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aligarjon

Posts: 2733
Joined: 09 September 2005

Why does it fail ? it sounds like a C3 to me.

Gary

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