Determining the size of already installed cable

[terryplumb]

Looks like 10mm² . If you look at the cable inside the shower ( turn power off first,before removing front cover) and look at its earth conductor ,if it is stranded copper it's 10mm cable. If it's solid single copper wire it isn't it's more likely 6mm.

 

[RandomGrinch]

Is there a cable size on that clip?
Some do have them, but others don't. If it is on there, and the cable fits very snugly without being squashed, then it's probably that size.

10 - 16 T&E

 

[conny]

@RandomGrinch, thanks for that. With my failing eyesight I still can't make it out though.