What size 3 core & earth for PIR/Light

[Damian30]

Hi,

Will be using a spark for the final connections but want to do the prep by installing the cable run.

Looking to take a fused spur from the socket ring to a PIR sensor which will then power an outside light. The PIR has an override for a permanent on and hence the 3 core + earth cable. Will be using a MK double switch for the PIR on or the permanent on. Not sure if 1mm or 1.5mm cable is needed for this, any views?

Many thanks,

Damian[/u]

 

[EFLImpudence]

1mm² has a current carrying capacity of 16A (no derating).
This will be more than ample for one light.

1.5mm², whilst being 50% larger, only has a CCC 25% higher, 20A.

However you should consult the electrician first, so that the cable runs and installation are satisfactory if you want him to certify it, although it will no longer be notifiable work after the end of this week.


Not aimed at the OP but he must have got the idea somewhere -
I am not sure where this obsession with using 1.5mm² originated.
Probably the same place as needlessly replacing tails with 25mm².