Steel Wire Armoured Cable and ceiling roses

[ColJack]

it doesn't include the rcd because you're highly unlikely to be drilling or nailing into a ceiling to hang a picture or a telly...

 

[electronicsuk]

it doesn't include the rcd because you're highly unlikely to be drilling or nailing into a ceiling to hang a picture or a telly...

I'm not sure that's the reason for excluding the RCD getout from 522.6.5 - after all, if there is no likelihood of damage to the cable in a ceiling, then why any requirements for earthed metallic protection or similar at all? It's more likely that we're allowed RCD protected cable runs <50mm deep in walls and partitions because to insist on cable incorporating an earthed metallic sheath would have been impractical, and rendered almost all existing installations non-compliant with no remedial action possible short of a rewire.

 

[riveralt]

it doesn't include the rcd because you're highly unlikely to be drilling or nailing into a ceiling to hang a picture or a telly...

So by providing an RCD in these circumstances I am meeting and exceeding the requirements of the regulations

 

[RF Lighting]

Perhaps, heaven forbid, the IEE made an error

No they didn't.

They are saying that ALL cables run <50mm from the surface of a ceiling must be either surrounded by earthed metal or have proper mechanical protection.

This is exactly consistant with the requirements of regulation 522.6.6

For regulation 522.6.6 (and regulation 522.6.5 if you like), the only time you do not have to provide earthed metal containment or mechanical protection at <50mm is when a cable is run in one of the prescribed safe zones.

There are no safe zones in a ceiling.

Using earthed metallic containment cable is far safer than relying on an RCD

 

[ColJack]

for a ceiling it's the floorboard nails / plasterboard screws they are protecting from usually done once and then left.

any screws etc that do clip a cable are generally out of reach of the homeowner. ( placing out of reach or barriers methods are in effect then )


in a wall the homeowner is likely to hammer nails in for pictures drill holes for radiators etc, which will be accessible..

 

[comms]

http://tpwcc.com/flexishield.html

Far easier

 

[RF Lighting]

Where can you buy it from and how much does it cost? Can you buy cut lengths or will you need to buy a full 100M drum?

A bit of 20mm galv tube and 2 end boxes with extention rings on would be much easier IMO

 

[ban-all-sheds]

They are saying that ALL cables run <50mm from the surface of a ceiling must be either surrounded by earthed metal or have proper mechanical protection.

No they aren't.

522.6.5 A cable installed under a floor or a bove a ceiling shall be run in such a position that it is not liable to be damaged by contact with the floor or the ceiling or their fixings. A cable passing through a joist within a floor or ceiling construction or through a ceiling support ( e.g. under floorboards ), shall:
.
.
.

 

[ColJack]

an interesting point..
so you think it would comply if I put a short piece of 3mm thick wall steel pipe through each joist?

they are only interested in nail / screw penetration so there's nothing stopping you laying it on the plasterboard in the floor void, or in this case clipping it to the ceiling between the battens you'll be putting up to support the new ceiling..

 

[nozspark]

522.6.5 A cable installed under a floor or a bove a ceiling shall be run in such a position that it is not liable to be damaged by contact with the floor or the ceiling or their fixings. A cable passing through a joist within a floor or ceiling construction or through a ceiling support ( e.g. under floorboards ), shall:

(i) be at least 50 mm measured vertically from the top, or bottom as appropriate, of the joist or batten, or

(ii) incorporate an earthed metallic covering which complies with the requirements of these Regulations for a protective conductor of the circuit concerned, the cable complying with BS 5467, BS 6346, BS 6724, BS 7846, BS EN 60702-1 or BS 8436, or

(iii) be enclosed in earthed conduit complying with BS EN 61386 and satisfying the requirements or these Regulations for a protective conductor, or

(iv) be enclosed in earthed trunking or ducting complying with BS EN 50085 and satisfying the requirements or these Regulations for a protective conductor, or

(v) be mechanically protected against damage sufficient to prevent penetration of the cable by nails, screws and the like.

Yup,
that's the exact same reg that the NICEIC tech help line pointed me at in a similar situation...

So as it's <50mm it needs RCD protection, but you must also use SWA, earthed metal conduit, pyro or something like flexishield...

Batt cables will sell cuts of "Guardian" cable, but it's x2 the price with a £15 small order/delivery charge.... +VAT
Other suppliers would only sell by the 100m drum!

 

[LoveRocket]

They are saying that ALL cables run <50mm from the surface of a ceiling must be either surrounded by earthed metal or have proper mechanical protection.

No they aren't.

522.6.5 A cable installed under a floor or a bove a ceiling shall be run in such a position that it is not liable to be damaged by contact with the floor or the ceiling or their fixings. A cable passing through a joist within a floor or ceiling construction or through a ceiling support ( e.g. under floorboards ), shall:
.
.
.

That's exactly how I understood it too. The OP can quite compliantly clip T+E to the surface of the original ceiling, or even better to the sides of the battons for the falsie.

 

[holmslaw]

..

 

[ban-all-sheds]

Maybe my suggestion of mini-joist hangers and 2" cable tray to carry cables running orthogonally to joists will come good...

 

[seasickstevie]

... orthogonally to joists ...

Nice word bas.

But surely that would be perpendicular to the joists (surly not what you mean).

 

[ban-all-sheds]

Yup, perpendicular would be another word.

Why should that not be what I mean?