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?

 

[Pete999]

What rating is the towel radiator?

 

[jkelly]

What rating is the towel radiator?

It’s IP64, thanks in advance

 

[Ian1981]

No as in how many watts?
Most come with a 1.0mm flex attached anyway but 1.0mm t&e for fixed wiring should be for lighting only.

 

[buzzlightyear]

Avarage 460 Watts, towel heated elments.

 

[jkelly]

No as in how many watts?
Most come with a 1.0mm flex attached anyway but 1.0mm t&e for fixed wiring should be for lighting only.

Ah sorry it’s only a very small one, 150watts

 

[Ian1981]

Ah sorry it’s only a very small one, 150watts

Will be fine

 

[westward10]

Can you show a pic of the junction box.

 

[goasis]

1.0mm t&e for fixed wiring should be for lighting only.

Certainly not wishing to start an argument but that's not strictly true is it?

 

[Ian1981]

Certainly not wishing to start an argument but that's not strictly true is it?

That’s what table 52.3 states (also see note 4) preceded by regulation 524.1, for final circuits anyway.
As it’s not from a lighting circuit, 1mm shouldn’t be used.

 

[Dave OCD]

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.

 

[Ian1981]

Then why ever limit 1mm to lighting circuits if by the load, it’s all that’s needed?
Even appendix 15 has 1.5 minimum to a socket fused down via a fused spur,

 

[Dave OCD]

You tell me mate, but would you always use 1.5 for a fixed load of under 1 amp ?

 

[Ian1981]

You tell me mate, but would you always use 1.5 for a fixed load of under 1 amp ?

I wouldn’t use 1mm in a fused spur due to the flimsy small csa in the terminals, even when doubled over.
That’s me tho.

 

[goasis]

That’s what table 52.3 states (also see note 4) preceded by regulation 524.1, for final circuits anyway.
As it’s not from a lighting circuit, 1mm shouldn’t be used.

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)

 

[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