Sep 07 2019 14:11
[shim]Can anyone steer me to somewhere other than 3000: 126.96.36.199.3 (a) (iii) with respect to selection of MCBs to provide required discrimination please?
for some reason i had in my head that a gap of one size was permitted... so a 32A submain could have a 20A mcb in the DB but think i might be wrong...
Sep 07 2019 17:27
[shim]Why would you look anywhere else than the clause that covers it?
Noting that 2018 edition changes this rule to 1.5 x instead of 2x; and that it's only a "should" in any case.
so as a rule-of-thumb; 2 standard rating steps assuming both are same trip curve.
Sep 07 2019 17:55
[shim]cheers Alec... appreciate the rapid response
Sep 07 2019 18:01
[shim]so do two 'shalls' and one 'should' make a 'should' or a 'shall' ?