How to calculate the power rating coming into a consumer box

[Viz]

Hi,

I have a consumer box with a 63A RCD main switch. How do I know what is the maximum power rating for the cabels coming into the box (I would like to install an electric shower and need find out if I need to get the mains feed upgraded - I'm not sure what rating the mains feed is).

Thanks in advance.
--

 

[dw3101]

your main fuse is likely to be 80A, what size are the cables.. 25mm or 16mm?

David

 

[Lectrician]

Your main fuse could be 60, 80, 100 even as low as 40 occasionally.

 

[Viz]

your main fuse is likely to be 80A, what size are the cables.. 25mm or 16mm?

David

The mains cables are about 8mm dia (including sheath).

Thanks for responding.

 

[andy]

Your main fuse could be 60, 80, 100 even as low as 40 occasionally.

the service fuse in my house is only 40A. the shower and cooker are often on together, along with other standard stuff. im surprised it hasnt blown yet

 

[Viz]

Your main fuse could be 60, 80, 100 even as low as 40 occasionally.

the service fuse in my house is only 40A. the shower and cooker are often on together, along with other standard stuff. im surprised it hasnt blown yet

This suggests that I should be okay with what I have. The supply company guarantee 100A in my area (free upgrade), but I didn't want to go for it if it is already at 100A. Hence the question

 

[andy]

Your main fuse could be 60, 80, 100 even as low as 40 occasionally.

the service fuse in my house is only 40A. the shower and cooker are often on together, along with other standard stuff. im surprised it hasnt blown yet

This suggests that I should be okay with what I have. The supply company guarantee 100A in my area (free upgrade), but I didn't want to go for it if it is already at 100A. Hence the question

if the fuse blows, then your obviously going over the fuse rating. in which case, youll prob be upgraded to 100A (or 80A)
the only way to find out what rating the service fuse is, is to look at it, which means breaking the seal