a spur from a spur?

[benplums]

whilst replacing the floor in my living room, I've noticed that the ring circuit has a spur from a junction box going to a double socket, and then another spur going from that to another double socket.

it all works (and I think has done for years) but I thought you weren't supposed to do this? Is it ok, or should I rewire to make the first socket part of the ring circuit and the second a normal spur?

 

[benplums]

or add an FCU between the junction box and the first socket?

 

[Albert]

Agree

 

[equitum]

Or, as its likely some other sockets are spurs off spurs (cowboys!), and assuming its in 2.5/1.5 T&E, downrate the fuse/mcb in the consumer unit from (I assume 30/32A) to 15/16A and the whole circuit is now effectively a radial and all is OK, providing you don't have too many high loads on the circuit, you wont blow/trip the fuse/mcb

 

[Albert]

You could use 20A MCB for this circuit, but make sure that you do not have 1.5mm2 cables, other wise IMO you will have to add the SFCU and reduce the fuse to 6A.

 

[equitum]

You could use 20A MCB for this circuit, but make sure that you do not have 1.5mm2 cables, other wise IMO you will have to add the SFCU and reduce the fuse to 6A.

13A fuse in the FCU may be OK dependant on correction factors, e.g. cables are in thermal insulation

 

[Albert]

If there is a 1.5mm2 cable I think that 13A (in the SFCU) might be a bit too close.

 

[equitum]

If there is a 1.5mm2 cable I think that 13A (in the SFCU) might be a bit too close.

maybe, maybe not, we don't know, but 1.5 is good for more than 13A ref method 1.

 

[Albert]

maybe, maybe not, we don't know,

Exactly my point, be on the safe side, a cable coming from an existing installation to/from a JB, you need only 500mm of insulation in any part of the circuit to half the carrying capacity...

 

[equitum]

err, I know...

You could use 20A MCB for this circuit, but make sure that you do not have 1.5mm2 cables, other wise IMO you will have to add the SFCU and reduce the fuse to 6A.

13A fuse in the FCU may be OK dependant on correction factors, e.g. cables are in thermal insulation

 

[Albert]

If you know, we agree...