Appendix C maximum demand by calculation, assessed per phase from the loads you place on each phase (Table C1 column 2, Table C2, Table C3). Blocks of living units, Table C4 and demand by measurement or limitation are not covered.
Maximum demand needs an internet connection. The AS/NZS 3000 diversity calculations run on our servers.
Results
Enter loads and press Calculate to see the after-diversity demand.
Method & disclaimer
Maximum demand by calculation under AS/NZS 3000:2018 Clause 2.2.2 and Appendix C: Table C1 column 2 for a single domestic installation or individual living unit, Table C2 columns 2 and 3 for non-domestic installations, or Table C3 energy demand.
Three-phase installations are assessed phase by phase from the loads connected to each phase, as in the Appendix C worked examples; the heaviest loaded phase governs. Balanced three-phase equipment shares its watts equally across the phases.
Watts are converted to current at 230 V. Motors, lifts, X-ray units and welders use nameplate currents. Groups marked "by assessment" use the demand you enter.
Not covered: blocks of living units (Table C1 columns 3 to 5), the switchboard diversity method (Table C4), final subcircuits (Table C9) and demand by measurement or limitation.
For guidance only. Verify against the current standard and your design documentation before relying on these results.
Which AS/NZS 3000 tables does this calculator use?
Table C1 column 2 for a single domestic installation or an individual living unit; Table C2 column 2 (residential institutions, hotels, boarding houses, hospitals, motels) or column 3 (factories, shops, stores, offices, business premises, schools, churches); or the Table C3 energy demand method for the listed non-domestic occupancies.
How does it handle three-phase installations?
Each phase is assessed from the loads you connect to it, and the heaviest loaded phase sets the maximum demand, as in the Appendix C worked examples. Balanced three-phase equipment can be entered once: its watts are shared equally across the phases and nameplate currents are added to every phase.
How is air-conditioning counted in a house?
Load group (d) of Table C1 counts fixed space heating and air-conditioning at 75% of the connected load. Where a house has both a cooling system and a heating system, only the system with the greater load is counted (Note 11).
What does the calculator not cover?
Blocks of living units (Table C1 columns 3 to 5), the switchboard diversity method of Table C4, final subcircuit loading (Table C9), and maximum demand determined by assessment, measurement or limitation under Clause 2.2.2.
How can I check the results?
The worked example presets load the loads from Appendix C Examples 1, 2, 4 and 5, so you can compare the result with the standard. The working lists each load group’s contribution on each phase.
