rcd protection on a armoured

[Peter Woodford]

guys,

i remember reading in the regs that a amoured cable does not need rcd protection is this right as i cant find the reg for it anywere. i am looking at running a amoured to a shed for a socket and light

cheers

 

[truckster]

Yep your'e right provided you bond the armour

 

[malcolmsanford]

Regulation 522.6.5 (ii) and 522.6.6 (i).

As your feeding a socket outlet from the SWA you might want to protect that socket under 411.3.3 by either fitting an RCD at the origin of the circuit or by fitting a BS 7288 RCD socket outlet.

If your earthing system is a TT you may find though that your unable to conform to the disconnection times with just an ordinary protection device due to the normal Ra value of the rod, and so would need to provide an RCD as additional protection

 

[i=p/u]

in the outbuilding

 

[malcolmsanford]

in the outbuilding

No go on ..................what is in the out building

 

[Deleted member 26818]

522.6.6(i) lists the cables that do not require RCD protection when concealed in walls.
All but one are armoured.

 

[i=p/u]

sockets in shed

 

[malcolmsanford]

I know i'm going to regret this ...and

 

[i=p/u]

they need to be rcd protected as your not going to run swa straight to socket outlet. are you????

 

[malcolmsanford]

What are you protecting with the RCD the cable or the socket?

 

[i=p/u]

the cable comming out of the socket, outside environment

 

[Deleted member 26818]

The socket would require 30mA protection, whereas if TT, the cable feeding the socket would need 100mA.

 

[malcolmsanford]

Unless your SWA is part of a TT system then there is no need to RCD protect the cable under any conditions outside or in, providing your not needing it for additional protection becasue as I said in my post you can't conform to the disconnection times becasue of a high Ra.

Under regulation 411.3.3 the socket is what requires the RCD protection and that can be achieved by a BS 7288 RCD socket.