Guides
Short, worked guides for the calculators. Each one states the inputs, shows the result the tool gives, and cites the clause or table behind it. AmpSize is a design aid. Verify results against the current standard.
For the idea behind a calculation rather than a worked case, read Learn, or see every clause the tools cite on the standards page.
Reader
Tool
10 guides
25 Sept 2026Commercial maximum demand with Table C2A tender-stage demand assessment for a commercial building using AS/NZS 3000 Table C2, with each group demand and the per-phase figure the tool returns.Maximum DemandAS/NZS 3000:2018 Cl 2.2.2AS/NZS 3000:2018 Table C2AS/NZS 3000:2018 Table C4
24 Sept 2026Prospective fault current at a main switchboardA 16 kA fault cleared in 0.1 s on 70 mm² copper XLPE, with the minimum conductor size, the withstand current and the k factor the adiabatic check returns.Fault RatingAS/NZS 3000:2018 Cl 2.5.4.1AS/NZS 3008.1.2:2017 Cl 5.3AS/NZS 3008.1.2:2017 Table 52
22 Sept 2026AS/NZS 3000 Table 8.1: maximum Zs explainedWhat Table 8.1 governs, why the B, C and D limits differ for the same 16 A rating, and a 30 m subcircuit that returns 0.89 ohm from the engine.Loop ImpedanceAS/NZS 3000:2018 Table 8.1AS/NZS 3000:2018 Table 8.2AS/NZS 3000:2018 Cl 5.7.2AS/NZS 3000:2018 Cl 5.7.4AS/NZS 3000:2018 Table 5.1AS/NZS 3008.1.2:2017 Tables 34-35
21 Sept 2026AS/NZS 3008 2025 edition: what AmpSize citesThe 2025 edition of AS/NZS 3008.1.1 is not held here. This page shows the 2017 tables the tool reads today, with a worked 100 A three-phase submain.Cable SizeAS/NZS 3000:2018 Cl 3.4AS/NZS 3008.1.2:2017 Tables 4-21AS/NZS 3008.1.2:2017 Table 14AS/NZS 3008.1.2:2017 Cl 4.5AS/NZS 3008.1.1:2025 not held
21 Sept 2026Voltage rise for a 5 kW solar inverter cableA 5 kW single-phase inverter 40 m from the switchboard on 10 mm² copper, with the rise in volts, the percent and the maximum length the tool returns.Voltage RiseAS/NZS 3000:2018 Cl 3.6.2 Note 3AS/NZS 3008.1.2:2017 Cl 4.5AS/NZS 3008.1.2:2017 Tables 30-35AS/NZS 4777.1:2016 Cl 3.3.3
19 Sept 2026AS/NZS 3000 Clause 3.6.2: voltage drop limitWhat Clause 3.6.2 governs, how the 5 percent budget splits across mains and subcircuits, and a 25 A run over 35 m that returns 2.6 percent from the engine.Voltage DropAS/NZS 3000:2018 Cl 3.6.2AS/NZS 3000:2018 Cl 3.6.2 Note 3AS/NZS 3008.1.2:2017 Cl 4.5Electricity (Safety) Regulations 2010 reg 61
19 Sept 2026Cable size for a 32 A single-phase 25 m runWork through a 32 A single-phase circuit over 25 metres in New Zealand. See every derating factor, the check that sets the size, and the result the tool gives.Cable SizeAS/NZS 3000:2018 Cl 3.4AS/NZS 3000:2018 Cl 2.5.3.1AS/NZS 3000:2018 Cl 3.6.2AS/NZS 3008.1.2:2017 Tables 4-21
19 Sept 2026Domestic maximum demand with Table C1Assess the maximum demand of a New Zealand house from Table C1, group by group, with a worked example that lands on 52.61 A on a single-phase supply.Maximum DemandAS/NZS 3000:2018 Cl 2.2AS/NZS 3000:2018 Table C1
19 Sept 2026Earth fault loop impedance and maximum ZsWhat earth fault loop impedance measures, how the maximum Zs check works, and a 32 A circuit on 6 mm² over 25 m that lands on 0.67 ohms against a 0.96 limit.Loop ImpedanceAS/NZS 3000:2018 Cl 5.7.4AS/NZS 3000:2018 Table 8.1AS/NZS 3000:2018 Table 5.1
19 Sept 2026Voltage drop with the mV/A·m methodHow the millivolt per amp metre method works, with a 32 A run over 25 metres on 6 mm² copper and the exact drop, percent and maximum length the tool returns.Voltage DropAS/NZS 3008.1.2:2017 Cl 4.5AS/NZS 3000:2018 Cl 3.6.2AS/NZS 3008.1.2:2017 Tables 30-35