Maximum demand calculator
I-estimate ang maximum demand para sa domestic o non‑domestic loads.
Reads AS/NZS 3000:2018 and Electricity (Safety) Regulations 2010. Tables checked 19 Sept 2026.
Subukan ang isang job 8
Nilalagyan ng halimbawang value ang bawat job. Palitan ang mga ito ng sarili mong value.
- Size a house mainThe maximum demand of a house with a heat pump, from Table C1.
- Work out commercial maximum demandThe maximum demand of a tenancy from Table C2.
- Work out demand for a block of unitsThe demand of twelve units, four on each phase.
- Work out demand with spa and floor heatingThe demand of a house with heating and a spa pool.
- Work out demand for a caféThe demand of a café with cooking and refrigeration.
- Work out demand for a small factoryThe demand of a workshop with lighting, sockets and motors.
- Work out demand for a three‑phase houseThe demand per phase of a large house.
- Work out demand for an office floorThe demand of a 400 m² office with air-conditioning.
Mga input
Worked example gamit ang mga default na input.
- Demand table
- Table C1 · domestic
- Installation
- Single domestic o isang living unit
- Mga phase
- Single phase
- Phase voltage
- 230 V
- Mga grupo ng load
- 4 row
Maximum demand
50.43A
- Kada phase
- 50.43A
- A(i) · Lighting
- 5A
- B(i) · Socket-outlets and permanently connected equipment up to 10 A
- 15A
- C · Ranges, cooking appliances and laundry equipment
- 17.39A
- F · Storage water heaters
- 13.04A
Design aid lang ang resultang ito. I-verify ito laban sa kasalukuyang standard.
Mga hakbang ng kalkulasyon
- Talaan ng demandC1 · single domestic
AS/NZS 3000:2018 Table C1
- A(i) · Lighting5A
AS/NZS 3000:2018 Table C1
- B(i) · Socket‑outlets and permanently connected equipment up to 10 A15A
AS/NZS 3000:2018 Table C1
- C · Ranges, cooking appliances and laundry equipment17.39A
AS/NZS 3000:2018 Table C1
- F · Storage water heaters13.04A
AS/NZS 3000:2018 Table C1
- Maximum demand50.43A
AS/NZS 3000:2018 Table C1
- Maximum demand kada phaseResulta50.43A
AS/NZS 3000:2018 Table C1
Tungkol sa calculator na ito
How this is calculated
The tool works out the maximum demand of an installation from its loads. It follows the load group method of AS/NZS 3000 Appendix C.
- Table. Table C1 covers domestic installations: one house or living unit, or a block of living units. Table C2 covers other installations. For Table C2 you pick the occupancy.
- Load groups. You enter each load in its group, such as lighting points, socket‑outlet points or kW of cooking. The tool lists only the groups the table assesses for your choice.
- Group demand. Each group has its own rule for its load. The tool applies that rule and gives the group demand in amperes. It converts each kW load at the phase voltage you enter.
- Living units per phase. A block of living units can take more than one phase. The tool then divides the units by the number of phases and rounds up. It reads the column for that number of units per phase.
- Total. The maximum demand is the sum of the group demands.
- Per phase. On three phases, the tool divides the total by three. That assumes you spread the load evenly over the phases. Where you cannot, allocate the loads per phase and check the heaviest phase.
| Step | Table or clause | What it decides |
|---|---|---|
| Domestic loads | AS/NZS 3000 Table C1 | The rule for each load group in a house or a block of living units |
| Other loads | AS/NZS 3000 Table C2 | The rule for each load group, by occupancy |
| Living units per phase | Table C1 Note 2 | The column a block of living units reads on more than one phase |
| Total and per phase | Table C1 or Table C2 | The sum of the groups and the share on each phase |
Phase voltage
Enter the phase voltage, line to neutral, such as 230 V. The tool converts every kW load at that voltage. The 400 V between lines would read every kW group 42 % low. On a three‑phase supply the tool refuses a line voltage and asks for the phase voltage.
Common installations, worked with the tool
Each line states its loads. Every line uses a phase voltage of 230 V.
- House on one phase. It uses Table C1 for one house. The loads are 30 lighting points, 25 socket‑outlet points, 8 kW of cooking and a 3 kW storage water heater. The maximum demand is 50.43 A.
- The same house on three phases. The maximum demand is 16.81 A per phase and 50.43 A over all phases.
- Block of 12 living units on three phases. Table C1 for blocks of living units, with the same load rows. The tool reads 4 units per phase. The maximum demand is 75 A per phase and 225 A over all phases.
- Office on three phases. It uses Table C2 for factories, shops and offices. The loads are 10 kW of lighting, 20 socket‑outlets and motors of 15 A, 10 A and 5 A. The maximum demand is 44.93 A per phase and 134.78 A over all phases.
New Zealand and Australia
AS/NZS 3000 Appendix C applies in both countries, so the tool has no country select.
Keep the result
Every input sits in the page address, so the link in your browser reproduces the calculation. The PDF button prints the result with its steps and table references. Saving a calculation to a project needs a free account.
See also: Commercial maximum demand with Table C2, Domestic maximum demand with Table C1 and Maximum demand and diversity.
Mga tanong
Design aid ang resulta. I-verify ito laban sa kasalukuyang standard.
Ano ang ginagawa ng maximum demand calculator?
Ina-apply ng tool ang demand rule para sa bawat load group na idadagdag mo. Inililista nito ang demand sa amperes para sa bawat group, pagkatapos iniuulat ang total demand at ang demand kada phase. Ipinapakita ng bawat linya ang table at ang column na pinanggalingan nito.
Aling AS/NZS 3000 table ang ginagamit ng maximum demand calculator?
Gumagamit ito ng AS/NZS 3000:2018 Table C1 para sa isang domestic installation o block ng living units. Gumagamit ito ng Table C2 para sa ibang installation, na may residential o commercial column. Piliin muna ang table at mode, dahil binabago nila kung aling rule ang sinusunod ng bawat load group.
Ano ang nagtatakda ng demand rule para sa bawat load group?
Itinatakda ng table at ng mode ang rule para sa bawat group. Kino-convert ng supply voltage ang mga group na nasa kilowatts tungo sa amperes. Hinahati ng bilang ng phase ang kabuuan. Sa living units mode, ang bilang ng unit sa bawat phase ang nagdidikta ng resulta. Ilagay ang kabuuang bilang ng unit at ang bilang ng phase.
Paano binibilang ang living units sa tatlong phase?
Hinahati ng tool ang bilang ng unit sa tatlo, gaya ng hinihingi ng Table C1 Note b. May mga group na tumatanggap ng listahan ng indibidwal na item, hindi ng iisang quantity. May mga group na ayon sa assessment at walang dinadagdag. May lumalabas na note sa itaas ng regulation 59 threshold.
Maaari ko bang i-share o i-save ang demand na kalkulasyon?
Oo. Nasa page address ang table, mode, voltage, phases at bawat load row. Kopyahin ang link para maipadala ang parehong demand assessment sa iba. Kailangan ng account para i-save ito sa ilalim ng project name. Ang kondisyon ng New Zealand ang default.
Mga worked example
- What size generator for a dairy shedSize a standby set for a dairy shed from its load list. The vacuum pump's start sets the size, then staggered steps, a drive and a soft starter shrink it.
- Fixed heating maximum demand with Table C1Adding 7.5 kW of fixed heating to a house under Table C1 group D, the demand each group contributes, and the 80 A line that reg 59 draws.
- Office maximum demand per phase with Table C2An office fitout load schedule assessed against AS/NZS 3000 Table C2, group by group, landing on 413.7 A across three phases and 137.9 A per phase.
- Factory power factor correction: 250 kW at 0.78A 250 kW factory load at 0.78 power factor lifted to 0.95. The kvar, the capacitor steps, the current saved, the kVA released and why the bank is detuned.
- Electrical estimating calculators NZ roundupA roundup of the calculators a New Zealand estimator uses at price stage, with a Table C2 fitout worked through to a demand of 102.95 A per phase.
- AS/NZS 3000 Tables C1 and C2: demand groupsWhat the demand group letters govern, when to use Table C1 or Table C2, and a commercial assessment that returns 276.26 A total and 92.09 A per phase.
Background
- Who may do electrical work in NZThe regulations that govern prescribed electrical work and its certification in New Zealand, named by number, with the paperwork abbreviations explained.
- IEC 60364 and the Wiring RulesIEC 60364 is the international series that AS/NZS 3000 stays aligned with. See how its parts are numbered, what TN-C-S, TT and IT mean, and where MEN fits.
- Maximum demand and diversityWhy consumer mains are smaller than the sum of the loads. The four methods of Cl 2.2.2, the Table C1 groups, and a house that lands on 70.18 A.
- PV and inverter basicsHow a grid-connected PV system connects to an installation, why voltage rise sets the inverter cable, and which standards the AmpSize tools cannot quote.
Mga clause at table na binabasa ng tool na ito
- AS/NZS 3000:2018 Cl 2.2Maximum demand
- Electricity (Safety) Regulations 2010 reg 59Part 1 and Part 2 designs
- AS/NZS 3000:2018 Table C1Maximum demand, single and multiple domestic installations
- AS/NZS 3000:2018 Table C2Maximum demand, non‑domestic installations
Bawat clause at table, kasama kung paano ito na-verify
Huling na-check ang mga table noong 19 Sept 2026.
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