Here's a question - I wonder if...

[rawhide]

Now, as you are probably aware the 17th stipulates that all conductors less than 50mm below the surface should protected by either RCD or an earthed metalic covering. ( i think thats how it put)

I don't think a kitchen light should be on RCD. HOt water, hot oil, gas flames, electric rings, sharpe knives. Maybe the odd dog or cat to trip over?

Far too dangeous if you ask me.

So can I do my switch drop in fp200. It's got a melalic case and its earthed. Then my kitchen light can go on mains. Along with the one in the room where the CU is.

Right? Wrong? What say you?

I've done the emergnecy light thing before. Never found one yet that will last more than 18 months

 

[batty]

fp200 cannot be used to get away with not using RCD a few cables can will look them up when I get a moment or perhaps someone else may say.

Batty

 

[matt.leung]

sounds a bit doggy to me... RCD it...

 

[Danny]

The protection has to withstand penetration from nails, screws, etc .. which is pretty difficult to achieve without metal conduit ...

If the drop is vertical then it doesnt require mechanical protection but does require an RCD ... OSG p60 ..

Surely it would make life easier to drop the cable in plastic capping in the chase and put it on an RCD ... by the time you've chased to accommodate the conduit you'll probably be at 50mm anyway ...

 

[Andy™]

So can I do my switch drop in fp200. It's got a melalic case and its earthed. Then my kitchen light can go on mains. Along with the one in the room where the CU is.

Right? Wrong? What say you?

I've done the emergnecy light thing before. Never found one yet that will last more than 18 months

FP200 is not designed for this. the metallic sheath is more for interference. stick a nail through it, and chances are the foil will fuse and burn away before the breaker trips. 8436 cable has a thicker metallic covering which can stand upto the fault current to trip a 32A breaker though

dont know what you mean by emergency light not lasting 18 month... they have rechargeable batteries and will last many years (even the cheap ones). you can also get conversion kits to convert a normal fluorescent light into an emergency fitting

 

[Andy™]

The protection has to withstand penetration from nails, screws, etc .. which is pretty difficult to achieve without metal conduit ...

it doesnt have to withstand penetration.... you could use SWA which wont stop a nail. it needs to be earthed though so no chance of hitting live but no earth for it to short against

 

[4285sct]

i thought any cable in a wall must be rcd protected

 

[Andy™]

i thought any cable in a wall must be rcd protected

no

 

[green-hornet]

Cables listed in the BS7671 can be used for installations, if a cable is not listed but complies with the requirements regarding protection it can be used without additional RCD protection but must be noted on your certificate as a deviation.

 

[rugbymacc]

if it's buried less than 50mm and no mech protected then yes

 

[Evans Electric]

If you are not happy with your lighting on an RCD you could do the switchdrop in Flexishield cable or similar . As andy says FP200 is no good but this stuff is. It is , however ,

 

[Andy™]

Cables listed in the BS7671 can be used for installations, if a cable is not listed but complies with the requirements regarding protection it can be used without additional RCD protection but must be noted on your certificate as a deviation.

by using a cable used complies with 522.6.6, then you have no devitation to make a note of

 

[green-hornet]

511. ?

If the installation is within the scope of the IEE Wiring Regulations BS 7671 (17th Edition), and as this cable type is not specifically listed in the Wiring Regulations, a verification of safety needs to be conducted in accordance with Clause 511, and appropriate details of the departures from BS 7671 entered on the installation certificate.

 

[0151]

i would suggest putting it on its own rcbo if its a big concern

 

[Andy™]

511. ?If the installation is within the scope of the IEE Wiring Regulations BS 7671 (17th Edition), and as this cable type is not specifically listed in the Wiring Regulations, a verification of safety needs to be conducted in accordance with Clause 511, and appropriate details of the departures from BS 7671 entered on the installation certificate.

522.6.6 cover just about any cable you could possibly use that doesnt need RCD'd, so would all comply with 511.1, and still no deviation to make a note of

 

[Andy™]

i would suggest putting it on its own rcbo if its a big concern

and if they still dont want it on RCD/RCBO... a nice bit of T2 down wall

 

[spinlondon]

Another thing to consider, is the switch drops on the rest of the circuit.

The RCD thing applies to the cabling on the whole of the circuit, not just the kitchen.

If you are seriosly not happy about the lights being on an RCD for safety reasons, then list it as a departure and put your reasons.

 

[rawhide]

If you are not happy with your lighting on an RCD you could do the switchdrop in Flexishield cable or similar . As andy says FP200 is no good but this stuff is. It is , however ,

 

[rawhide]

dont know what you mean by emergency light not lasting 18 month... they have rechargeable batteries and will last many years (even the cheap ones). you can also get conversion kits to convert a normal fluorescent light into an emergency fitting

EMERGENCY LIGHT THING: The CCU was in the cupboard under the stairs which doubled up as a cloak room. I 3-plated the light and fitted a maintained bulkhead - Brand new. A little over 12 months later it packed up. So I fitted another one brand new. 12 months later that packed up. At this point I decided to get fed up and was selling that particular house, so I then fitted a standard fitting from B&Q. It just failed to operate I think the change over relay had gotten stuck. (My last house was a TT supply hence me wanting an emergency fitting above the CCU)

 

[rawhide]

and if they still dont want it on RCD/RCBO... a nice bit of T2 down wall

um really nice.