6mm Earth and Main protective bonding conductors

[Michaelwgroves]

Why must something be wrong? I haven't checked the figures but that is within the ballpark of what you would normally expect for a small supply like this.

Just seems so small when new installations require 16mm

 

[Ian1981]

Just seems so small when new installations require 16mm

Because everyone used the tables in bs 7671 rather than the calculation
Plus the DNO may stipulate the CSA

 

[Michaelwgroves]

Just so this sinks in, I calculated fault current 1,045A using measured Ze. But I could have equally used the fault current calculated by my meter of 1,080 A ?

 

[davesparks]

Just seems so small when new installations require 16mm

Instead of blindly following a book try actually thinking about what determines the size and what the conductor is required to do.

It is not required to carry the current for any appreciable length of time, it only has to carry it for maybe one tenth of a second.
To take a very simplistic view look at a piece of 60A fuse wire, as long as your earthing conductor is bigger than that it will do its job.

 

[Michaelwgroves]

I like you analogy.