Recommended cable sizes for bridges

[SirLouen]

Lets say that the main circuit breaker has 40A, RCD 40A, we don't have a comb busbar, and we have to do bridges manually between 5 MCb with 25A, 20A, 16A, 16A and 10A respectively, which is the site that must be used in the inner sections

I provide a diagram to show which are the cables I'm referring to, labelled as: A, B, C, D, E and F

PS: I'm using the 1P+N model because it's common where I live, but you can also imagine that instead of two poles there is only the live wire between MCBs and RCD. I only need to understand the best sizes for wiring.

 

[poni]

not a thing I would do, but 40A MCB then 40A cable

 

[SirLouen]

not a thing I would do, but 40A MCB then 40A cable

You just call it "40A cable"?
In my country they are measured in square milimiters. Like 10 mm2, 6 mm2. There is no "40A cable"

In fact this feels kind of weird because for example in this page, they call 40A cable to a 6 mm2, which generally 10 mm2 is generally more widely accepted to be the best match for 40A circuits.

 

[Geoff1946]

Normal distribution cable ratings don't really apply in the very short lengths used here. I'm sure that the 6mm would be fine

 

[poni]

You just call it "40A cable"?

the cross-sectional area of the cable depends on so much
1. type of cable
2. length of cable
3. temperature of the area it's fitted.

if you use pryo you might be able to use 4mm
if you use PVC and it's a boiler house then you might need 16mm