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The long form would be a detailed calculation based on the operating curve data for the particular devices. The short form lets us get on the the job using a 'deemed to comply"; regardless of whether it actually complies. The fact that the example doesn't quite match (by 1 A or 3.1%) doesn't invalid...

Balderdash.
Wiring rules clearly allow for a reduction in CCC without an additional protective device in these circumstances.
Each branch is a foxed load, so need only be sized for that load.

2.3.3.3 (currently cited edition) requires ALL main switches to be readily accessible. This includes domestic. The ONLY Exception is for installations of a few specific types that are located on public land. So the issue is whether a typical domestic swbd door either as supplied ex-factory or for a ...

"for the line side feed to RCDs or RCBOs, the clause doesn't apply."

I don't think that's true. I can see nothing that exempts these connections from being required to be identified.

They key to this apparent anomaly is the wording "deemed to be provided".
That means it doesn't matter whether the actual long-form calculation works, all that matters is the short-form "x2" calculation

The only way to get reliable discrimination between RCDs is by having a time delay (ie upstream device is Type S). That's because RCDs do not limit the current, they only react to it; and the max trip times for any Type of RCD do not vary depending on residual current rating - an 100 mA Type A must ...

The actual wording of the ELV Exception from being PEW [Schedule !, cause 2(b) & (c)] is not about the voltage of the array (or whstever) but about whether or not the ELV fittings are "associated with" a supply at above ELV. So a lawyer could argue that any PV array supplying an inverter for LV supp...

safety services eg fire pumps, , lifts, etc 9see 7.3) must each have separate main switch. For outbuildings; if supply > 100A + has a switchboard, or if supplied by more than one submain [2.3.4] Back to domestic; each separate tenancy must have own main switch; though not necessarily within the tena...

I am not certain of the reason(s) for the restriction.

Note that in 1.417 (2007+A1+A2), definition of "cable" includes "a single cable core";
and 1.4.19 "cable core" is any "conductor" with its insulation.
So any individual cable core within a multicore cable is itself a cable.

"3018 has been discontinued;. Basically it was targetted at the domestic sector, on the basis that domestic work is simpler and those doing it don't need to have the entore book. But it was never much used in NZ; and with almost all Standards that we need being available "free" via EWRB there's no s...

The conductors of a single multicore cable would be a group of single-core cables; so the way I read it parallelling 2.5s within a single multicore is forbidden, same as for multiple multicores. Reading it any other way is basically ignoring the underlying theory. That said, I believe this clause wo...

True there's a good chance an old MES will not meet ESR 113; so we should always be prepared for the upgrade. Also sometimes it may be that the alteration to the mains, eg shorter / larger conductors, may have an adverse effect on safety of the MES part of the installation; contrary to ESR 13. But m...

Technically it's not the Inspector who must check that the installation has a main earthing system (MES). ESR 73A(1)(e)(iv) makes the person-about-to (re)connect the installation responsible for this. For undergrounding mains; that will be a linesman. However the person doing the job should be aware...