UK 1mm cable to carry 13a

[jkelly]

My towel heater used to go into a 13a fused switch, which then went into a junction box fixed inside a backbox on the wall.

Since re-fitting the bathroom, in order to move the towel radiator, I ran a 1 meter length of 1mm twin+earth cable behind the drywall from the junction box into the new location for the fused switch.

I have now plastered the walls, and suddenly worried is 1mm cable enough to carry 13a?

 

[Ian1981]

OK, interesting, thanks, does that mean that any circuit that isn't lighting is defined as a power circuit? Surely if you've done the calcs and selected and appropriate ocpd for the cable thats what matters? Genuine question, ('tone' can be misinterpreted in print)

Yes, if your wiring a central heating circuit from the CU to the spur, it should be 1.5mm 2 minimum as per the table as it’s not a lighting circuit, regardless of the load being small enough for a small csa.

 

[Dave OCD]

Fair enough Ian , I find it connects perfectly well doubled over, but it might depend on the accessory and size of terminal.

 

[Ian1981]

Fair enough Ian , I find it connects perfectly well doubled over, but it might depend on the accessory and size of terminal.

Just my preference, I hate the stuff in larger terminals
[automerge]1587754982[/automerge]

But if it's only from the outgoing side of a switched fused spur [appropriately fused] and running a load of under 1 amp I think it would be ridiculous to use anything bigger.

Your probably right,

 

[WallaceP]

I have always hated that regulation, I don’t get why lighting and power circuits are different, if the CSA is suitable what is the problem? It also then raises questions over fans wired into lighting circuits. I feel it’s a way to push out the use of 1mm eventually, but I find it hard to understand why.

 

[Ian1981]

I have always hated that regulation, I don’t get why lighting and power circuits are different, if the CSA is suitable what is the problem? It also then raises questions over fans wired into lighting circuits. I feel it’s a way to push out the use of 1mm eventually, but I find it hard to understand why.

The notes given in table 52.3 (note4) clearly states 1mm is fine for say a bathroom extractor fan as it’s part of the lighting circuit if wired from the lighting circuit