Hi all,

I have tried searching the forum for this but for some reason the search isnt working? Anyway, apart from SWA, Conduit and the flexishield cable BS8436, does anyone know of any other cable that can be installed and offer the same protection? I am looking to install across a ceiling to the centre of a room, I have no access to floorboards and cannot achieve sufficient depth to avoid using one of the above.
Any ideas appreciated

regards
Misterben

is this in a house?
if its going to be on the ceiling and run surface whats wrong with T&E in trunking?

Hi Dave,

yes it is in a house but needs to be plastered over.

regards
Misterben

RCD?

Apart from 8436, conduit, swa, and MICC, what more could you need?

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Lack of planning on your part doesn't make it an emergency on mine....

Every man has to know his limitations- Dirty Harry

Safe zones don't apply to ceilings so assuming it's only a 1.00mm t/e why not cut a channel in the plasterboard, fit the cable and then plaser over and rcd/rcbo the circuit? Not the best way of doing it but if you can't get above and you don't want it on the surface there's not much alternative!
Can't honestly say i'd like to do it that way but I can't see it's really against any regulation?

Dave.

Hi,

Safe zones dont apply to ceilings? I read it that they have to be greater than 50mm or mechanically protected,maybe I have misinterpreted it?
It is outside a zone as far as I can see, therefore was going to use 8436 as it is shielded and relatively small in diameter compared to 20mm tube or SWA.

regards
Misterben

have to be greater than 50mm or mechanically protected,maybe I have misinterpreted it?
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Or rcd protected.

In normal circumstances i.e on a wall inside zones obviously it would be on an RCD most of the time.
But if I wasnt inside a zone then it would need to be protected by SWA or earthed system such as conduit. Unless of course you could achieve 50mm depth.
I am just looking at this being outside of a zone? Ive never really had to run a cable in such a manner before!

regards

Misterben

RCD protection is not an option for cables in ceilings.
The 50mm and the mechanical protection, only apply where the cable passes through joists.

Hi Spin,
So are you saying that the cable cant be installed in plaster on a ceiling unless its greater than 50mm depth?

regards
Misterben

Whether whithin zones or not cables <50mm below the surface need to be either mechanically protected or be of a a type that doesn't need it or rcd protected, so what's the problem?

The 50mm and the mechanical protection, only apply where the cable passes through joists.
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What on earth are you talking about Spin?

Its been a long day! But I think your suggestion of T+E across a ceiling outside the safezone has thrown me somewhat.
So going by that we are allowed to run mechanically unprotected cables ouside of zones as long as they are on an RCD?
Maybe you are right but I think I will run BS8436 across the ceiling buried at a sufficient depth to conceal with plaster.
Thanks for input

regards
Misterben

There are no safezones on ceilings just as there are no safe zones on floors misterben!

I reiterate.
RCD protection is not an acceptable method of additional protection for cables in ceilings.
Further, it is only an acceptable method where the cables are run in prescribed zones.
Provide RCD protection for the cables by all means.
However doing such dose not abrogate the requirement to provide an acceptable method of additional protection.

The requirement to provide additional protection for cables concealed above ceilings or below floors, only applies where the cables pass through joists.

I think that there are safe zones in ceilings. That is either through the centre of the joist or above 50mm. This stipulation has been around for ages. Certainly long before Building control part P and additional protection by the use of RCDs.

However, look at it logically. Will your client be using the ceiling to hang pictures, mosquito net hooks, screwed fixings for mirrors to the ceiling?

However, IMO, circuit runs buried in the fabric of the building should now be protected either by a metallic earthed covering or/and RCD protected.

Legh

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Why do we need Vernier Calipers when we have container ships?

http://www.leghrichardson.co.uk

"Science has overcome time and space. Well, Harvey has overcome not only time and space - but any objections."

Is this a wind up?
Can none of you actually read the Regulations?
RCD protection is not an acceptable method of providing additional protection for these cables.
If it were, then it would be in the list of acceptable methods.
I don't have an electronic copy of the Regulations to be able to copy and paste, and can't be asked to type it out.
I suggest that you look it up yourselves, the number is 522.6.100.

Neither does it state implicitly in 314.1 (iii) that RCDs should be used but by inference, common sense and developing technologies and following the spirit of the regulations as guidance and not as a statutory document will you be able to see the light.

Legh

-------------------------
Why do we need Vernier Calipers when we have container ships?

http://www.leghrichardson.co.uk

"Science has overcome time and space. Well, Harvey has overcome not only time and space - but any objections."

through the centre of the joist or above 50mm.
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Agreed Legh but I don't think of that as "safe zones". Safe zones to me are routes running inline with an accessory or whithin 150mm of a corner or top of a wall, it would be difficult to use that system in a ceiling wouldn't it!

Dave.