ARWadsworth wrote:

Page 96 of OSG. It is important to ensure that distribution boards or
consumer units are of sufficient rating to take the total load connected to
them without the application of any diversity.

What a load of cock. [...]

The footnotes at the bottom of page 96 only apply to the corresponding
(starred or daggered) rows 5 to 8 in Table 1B - i.e. to stated the water
& space heating loads.

Common sense has to be applied.

Yes - Table 1B used literally does tend to overestimate the MD, IMHO.
e.g. in the case of this thread we have 32 A for the first ring, about
25 A for the remaining two (at 40%) and say 22 A for a 12 kW cooker
(first 10 A plus 30% or remainder), giving a total of ~79 A - so the 63
A RCD really should be uprated. In practice though, in 99.9% of cases,
it will be quite OK.

--
Andy