Which Table C2 column applies to my building?

Table C2 has two demand columns chosen by occupancy. Column 2 covers residential institutions, hotels, boarding houses, hospitals, accommodation houses and motels. Column 3 covers factories, shops, stores, offices, business premises, schools and churches. Column 3 is the harder assessment: lighting goes to full connected load instead of 75%, general 10 A outlets go from 400 W to 750 W each after the first, and the leftover items in the socket-outlets-over-10 A and appliance groups count at 75% instead of 50%. Motors are the odd one out: in Column 3 the second-biggest motor counts at 75%, but everything after it still counts at 50%, same as Column 2.

How does Table C2 apply diversity?

Diversity sits inside each load group, not in one factor at the end. Lighting is a straight percentage of connected load. General 10 A outlets use a watts-for-the-first-outlet plus watts-for-each-extra allowance. Socket-outlets over 10 A, appliances and EV chargers count the biggest item in full and the rest at a reduced percentage. Motors add a middle step in Column 3: biggest in full, second at 75%, the rest at 50%. Lifts are their own rule again: the biggest lift motor counts at 125% to cover starting current, the next at 75%, the rest at 50%. Because the table does the diversity for you, always enter connected loads, never a figure you have already discounted.

Can Table C2 be used for mixed-use buildings?

Yes, for the non-domestic portion. Assess the dwellings under Table C1 and the retail, office or commercial portions under Table C2 (or the Table C3 energy demand method at concept stage), then sum the results at the main switchboard. Table C1 also refers its communal lift load group (k) back to Paragraph C2.4.1 and Table C2, so the lifts serving a residential block are assessed with the Table C2 group (e) expression.

What is the difference between Table C1 and Table C2 in AS/NZS 3000?

Table C1 covers single and multiple domestic installations, and selects its assessment column from the number of living units per phase. Table C2 covers non-domestic installations and selects its column from the occupancy type: Column 2 for hotels, hospitals, motels and similar residential institutions, Column 3 for factories, shops, offices, schools and churches. A mixed-use building uses Table C1 for the dwellings and Table C2 for the non-residential portions, summed at the main switchboard.

Which loads belong in each Table C2 group?

Group (a) lighting; group (b) socket-outlets (≤10 A, ≤10 A in buildings with permanent heating or cooling, and >10 A); group (c) appliances for cooking, heating and cooling including instantaneous water heaters, plus EV charging equipment; group (d) motors; group (e) lifts; group (f) fuel dispensing units; group (g) heating elements for thermal storage, pools, spas and saunas; group (h) welding machines; group (i) X-ray equipment; group (j) other equipment by assessment. The ElecAS calculator labels every input with its Appendix C group letter.

Are lifts assessed as motors under Table C2?

No. Lifts are their own load group (e) and are assessed at 125% of the largest lift motor, plus 75% of the next largest, plus 50% of the remaining lift motors, in both columns. Ordinary motors (fans, pumps, compressors) are group (d), which uses full load of the highest-rated motor plus 50% of the remainder in Column 2, or plus 75% of the second highest and 50% of the remainder in Column 3.

Can I use Table C2 for a single-tenant office fit-out?

Yes. Table C2 is the correct table for any non-domestic installation including a single office tenancy, which is a Column 3 occupancy. Enter the connected load per group and the calculator applies the published Column 3 expressions.

Does Table C2 cover EV charging stations?

Yes. Charging equipment associated with electric vehicles is load group (c)(ii) of Table C2, assessed as the full connected load of the highest-rated unit plus 75% of the full load of the remainder, in both Column 2 and Column 3. The ElecAS calculator keeps EV chargers as their own line so the charging contribution to the consumer mains demand is visible in the report.

ElecAS

Table C2 Maximum Demand Calculator: Non-Domestic Installations to AS/NZS 3000:2018

Free, browser-based maximum demand calculator implementing AS/NZS 3000:2018 Appendix C Table C2: the deemed-to-comply method for non-domestic electrical installations. It implements all ten Table C2 load groups: (a) lighting, (b) socket-outlets split into those not exceeding 10 A, those in buildings with permanently installed heating or cooling, and those exceeding 10 A, (c) appliances for cooking, heating and cooling including instantaneous water heaters plus electric vehicle charging equipment, (d) motors, (e) lifts, (f) fuel dispensing units, (g) heating elements for thermal storage, water heating, pools, spas and saunas, (h) welding machines, (i) X-ray equipment and (j) other equipment by assessment. Both published columns are supported and are selected by occupancy: Column 2 for residential institutions, hotels, boarding houses, hospitals, accommodation houses and motels, and Column 3 for factories, shops, stores, offices, business premises, schools and churches. The highest-plus-remainder groups take a list of items and identify the highest-rated one for you: socket-outlets over 10 A and cooking, heating and cooling appliances at full rating plus 50% (Column 2) or 75% (Column 3) of the remainder, EV chargers at full rating plus 75% of the remainder in both columns, motors at full load of the largest plus 50% of the remainder or, in Column 3, plus 75% of the second largest and 50% of the rest, and lifts at 125% of the largest lift motor plus 75% of the next plus 50% of the remainder. The result is a demand in amperes per phase with a line-by-line breakdown naming each group and the expression applied, exportable as a branded PDF report.

Key facts

Table C2 has two demand columns chosen by occupancy: Column 2 for residential institutions, hotels, boarding houses, hospitals, accommodation houses and motels; Column 3 for factories, shops, stores, offices, business premises, schools and churches.
The load groups are (a) lighting, (b) socket-outlets, (c) appliances for cooking, heating and cooling plus EV charging equipment, (d) motors, (e) lifts, (f) fuel dispensing units, (g) thermal storage and pool, spa and sauna heating elements, (h) welding machines, (i) X-ray equipment and (j) other equipment by assessment.
Lighting is assessed at 75% of connected load in Column 2 and at full connected load in Column 3.
Most groups use a highest-plus-remainder form: socket-outlets over 10 A and cooking, heating and cooling appliances take the full rating of the highest-rated item plus 50% (Column 2) or 75% (Column 3) of the remainder.
Lifts are group (e), separate from motors in group (d): 125% of the largest lift motor, plus 75% of the next largest, plus 50% of the remaining lift motors, in both columns.
EV charging equipment is group (c)(ii): the full connected load of the highest-rated unit plus 75% of the remainder, in both columns.

Who this page is for

Electrical engineers, building services designers, estimators and contractors sizing consumer mains and submains for offices, retail, warehouses, factories, schools, churches, hotels, motels and hospitals in Australia and New Zealand, and anyone assessing the communal lift and motor loads that Table C1 refers back to Table C2.

Relevant standards

AS/NZS 3000:2018 (Wiring Rules: Clause 2.2.2 determination of maximum demand by calculation, assessment, measurement or limitation)
AS/NZS 3000:2018 Appendix C Table C2 (Maximum demand: non-domestic electrical installations, load groups (a) to (j), Columns 2 and 3)
AS/NZS 3000:2018 Appendix C Paragraph C2.5.2 (assessment of welding machines, taking power factor correction into account)

What this tool helps with

Implements all ten AS/NZS 3000:2018 Table C2 load groups: (a) lighting, (b) socket-outlets, (c) cooking, heating and cooling appliances plus EV charging equipment, (d) motors, (e) lifts, (f) fuel dispensing units, (g) thermal storage, pool, spa and sauna heating elements, (h) welding machines, (i) X-ray equipment and (j) other equipment by assessment.
Supports both published occupancy columns: Column 2 for residential institutions, hotels, boarding houses, hospitals, accommodation houses and motels, and Column 3 for factories, shops, stores, offices, business premises, schools and churches. The two descriptions the table itself uses, so the column choice is unambiguous.
Assesses lighting at 75% of connected load in Column 2 and full connected load in Column 3, and socket-outlets not exceeding 10 A at 1000 W for the first outlet plus 400 W (Column 2) or 750 W (Column 3) each additional: or 1000 W plus 100 W each additional where the building has permanently installed heating or cooling.
Ranks multi-item groups automatically so the highest-rated item is identified: socket-outlets over 10 A and cooking, heating and cooling appliances at full rating plus 50% or 75% of the remainder, and EV charging equipment at full rating plus 75% of the remainder in both columns.
Keeps lifts in their own group (e) rather than lumping them with motors (125% of the largest lift motor, plus 75% of the next largest, plus 50% of the remaining lift motors), which is the grouping error that most often undersizes a commercial consumer mains.
Covers the specialist groups other calculators skip: fuel dispensing units (first motor at full load, second at 50%, additional at 25%, lighting at full load), thermal storage and pool, spa and sauna heating elements at full-load current, welding machines under Paragraph C2.5.2, and X-ray equipment at 50% of the largest unit with additional units ignored.
Shows a line-by-line breakdown giving each group, its input, the expression applied ("Highest 100% + Rest 75%", "1st 125% + 2nd 75% + Rest 50%") and its contribution in amperes, with optional overall diversity and spare capacity added as their own lines.
Exports a branded PDF maximum demand report with full project metadata, ready for the design submission and compliance record.
Built and reviewed by a Chartered Professional Engineer (CPEng, NER, NSW DBP, NSW PRE, APEC, IntPE Aus): see the Verification page for the testing and review process.

How to calculate maximum demand using AS/NZS 3000 Table C2

Pick the Table C2 column for the occupancy: Choose Column 2 (residential institutions, hotels, boarding houses, hospitals, accommodation houses and motels), or Column 3: factories, shops, stores, offices, business premises, schools and churches. The column sets the diversity factors for lighting, socket-outlets, appliances and motors.
Set the phases and power factor: Select single-phase (230 V) or three-phase (400 V) consumer mains and enter the project power factor. Connected loads are entered in watts and converted to amperes per phase.
Sort the connected loads into the Table C2 groups: Group (a) lighting; (b) socket-outlets, split into ≤10 A, ≤10 A in buildings with permanent heating or cooling, and >10 A; (c) cooking, heating and cooling appliances plus EV charging equipment; (d) motors; (e) lifts; (f) fuel dispensing units; (g) thermal storage, pool, spa and sauna heating elements; (h) welding machines; (i) X-ray equipment; (j) everything else by assessment.
Enter each item at its connected load: For the highest-plus-remainder groups, add each appliance, motor, lift or charger as its own item at full connected load. The calculator ranks them and applies the full rating to the highest and the group factor to the remainder: do not pre-diversify the inputs.
Add any overall diversity and spare capacity: Apply a project diversity factor or a spare-capacity percentage only where the design brief requires them. Both are applied after the Table C2 groups and appear as separate lines so the Appendix C figure stays visible.
Review the breakdown and export the report: Check each group's contribution and the expression used against your load schedule, then export the branded PDF for the design submission.

AS/NZS 3000:2018 Table C2: maximum demand for non-domestic installations

What Table C2 covers

AS/NZS 3000:2018 Appendix C Table C2 ("Maximum demand: non-domestic electrical installations") is the deemed-to-comply calculation method for consumer mains and submains serving any installation that is not a dwelling: offices, retail, factories, warehouses, schools, hospitals, hotels and motels, along with the communal lift and motor loads that Table C1 refers back to Table C2 for.

The table has three columns. Column 1 names the load group. Column 2 gives the assessment for residential institutions, hotels, boarding houses, hospitals, accommodation houses and motels. Column 3 gives the assessment for factories, shops, stores, offices, business premises, schools and churches. The ElecAS Table C2 calculator asks for the building type using those two descriptions verbatim, so there is no ambiguity about which column your project falls in.

The ten load groups and their expressions

Group (a) lighting, other than the lighting inside a fuel dispensing unit, which sits in group (f), is assessed at 75% of connected load in Column 2 and at full connected load in Column 3.

Group (b) covers socket-outlets in three parts. Outlets not exceeding 10 A are assessed as 1000 W for the first outlet plus 400 W (Column 2) or 750 W (Column 3) for each additional outlet. Where the building has permanently installed heating or cooling equipment, that becomes 1000 W for the first outlet plus 100 W for each additional outlet in both columns. Socket-outlets exceeding 10 A take the full current rating of the highest-rated outlet, plus 50% (Column 2) or 75% (Column 3) of the full rating of the remainder.

Group (c)(i) covers appliances for cooking, heating and cooling including instantaneous water heaters: full connected load of the highest-rated appliance plus 50% (Column 2) or 75% (Column 3) of the remainder. Group (c)(ii) covers charging equipment associated with electric vehicles: full connected load of the highest-rated unit plus 75% of the remainder, in both columns.

Group (d) motors take the full load of the highest-rated motor plus 50% of the remainder in Column 2; Column 3 takes the full load of the highest-rated motor, plus 75% of the second highest, plus 50% of the remainder. Group (e) lifts are assessed identically in both columns as 125% of the largest lift motor, plus 75% of the next largest, plus 50% of the remaining lift motors, where the full-load current means the current drawn lifting maximum rated load at maximum rated speed.

Group (f) fuel dispensing units take the first motor at full load, the second at 50%, additional motors at 25%, and their lighting at full connected load. Group (g) (heating elements associated with thermal storage heaters, water heaters, space heaters, swimming pools, spas and saunas) takes full-load current. Group (h) welding machines are assessed under Paragraph C2.5.2 taking power factor correction into account. Group (i) X-ray equipment takes 50% of the full load of the largest unit, with additional units ignored. Group (j) is everything else, by assessment.

Where Table C2 assessments go wrong

The most frequent grouping error is putting a lift in group (d) with the other motors. Lifts are group (e) and carry a 125% factor on the largest machine to cover starting current: assessing a lift as an ordinary motor understates the demand. Conversely, a kitchen exhaust fan or a pump is an ordinary motor in group (d), not a lift.

The second is entering an already-diversified figure. Every Table C2 expression takes connected load and applies the diversity itself, so entering a "design load" that has had a factor applied to it diversifies the same load twice and undersizes the mains.

The third is column choice. A hotel and an office are both non-domestic, but a hotel is a Column 2 occupancy and an office is a Column 3 occupancy, and Column 3 is the more onerous assessment for lighting (full connected load rather than 75%) and for the remainder terms in groups (b)(i), (b)(iii), (c)(i) and (d).

What the calculator does

The ElecAS Table C2 calculator implements all ten load groups with the published Column 2 and Column 3 expressions. Each group can be switched on or off, multi-item groups (socket-outlets over 10 A, appliances, EV chargers, motors, lifts, X-ray units) accept a list of items and sort them internally so the highest-rated item is identified for you, and the breakdown records the expression applied to each group: "Highest 100% + Rest 75%", "1st 125% + 2nd 75% + Rest 50%" and so on.

Loads are entered in watts with a project power factor, and converted at 230 V single-phase or 400 V three-phase to give the demand in amperes per phase. An optional overall diversity factor and a spare-capacity percentage can be applied on top of the Table C2 result where the design brief calls for them, and both are shown as separate lines in the breakdown and the exported PDF report rather than being folded silently into the total.

Where the installation type is one of the occupancies tabulated in Table C3 and the design is still at the floor-area stage, the Table C3 energy demand method is the faster route: see the Table C3 calculator.

Reviewed by

Wisam Tozah: Associate Electrical Engineer. B.Eng (Electrical), MIEAust, CPEng, NER, NSW DBP, NSW PRE, APEC, IntPE(Aus). See how these calculations are verified. LinkedIn.

Frequently asked questions

Which Table C2 column applies to my building?: Table C2 has two demand columns chosen by occupancy. Column 2 covers residential institutions, hotels, boarding houses, hospitals, accommodation houses and motels. Column 3 covers factories, shops, stores, offices, business premises, schools and churches. Column 3 is the harder assessment: lighting goes to full connected load instead of 75%, general 10 A outlets go from 400 W to 750 W each after the first, and the leftover items in the socket-outlets-over-10 A and appliance groups count at 75% instead of 50%. Motors are the odd one out: in Column 3 the second-biggest motor counts at 75%, but everything after it still counts at 50%, same as Column 2.
How does Table C2 apply diversity?: Diversity sits inside each load group, not in one factor at the end. Lighting is a straight percentage of connected load. General 10 A outlets use a watts-for-the-first-outlet plus watts-for-each-extra allowance. Socket-outlets over 10 A, appliances and EV chargers count the biggest item in full and the rest at a reduced percentage. Motors add a middle step in Column 3: biggest in full, second at 75%, the rest at 50%. Lifts are their own rule again: the biggest lift motor counts at 125% to cover starting current, the next at 75%, the rest at 50%. Because the table does the diversity for you, always enter connected loads, never a figure you have already discounted.
Can Table C2 be used for mixed-use buildings?: Yes, for the non-domestic portion. Assess the dwellings under Table C1 and the retail, office or commercial portions under Table C2 (or the Table C3 energy demand method at concept stage), then sum the results at the main switchboard. Table C1 also refers its communal lift load group (k) back to Paragraph C2.4.1 and Table C2, so the lifts serving a residential block are assessed with the Table C2 group (e) expression.
What is the difference between Table C1 and Table C2 in AS/NZS 3000?: Table C1 covers single and multiple domestic installations, and selects its assessment column from the number of living units per phase. Table C2 covers non-domestic installations and selects its column from the occupancy type: Column 2 for hotels, hospitals, motels and similar residential institutions, Column 3 for factories, shops, offices, schools and churches. A mixed-use building uses Table C1 for the dwellings and Table C2 for the non-residential portions, summed at the main switchboard.
Which loads belong in each Table C2 group?: Group (a) lighting; group (b) socket-outlets (≤10 A, ≤10 A in buildings with permanent heating or cooling, and >10 A); group (c) appliances for cooking, heating and cooling including instantaneous water heaters, plus EV charging equipment; group (d) motors; group (e) lifts; group (f) fuel dispensing units; group (g) heating elements for thermal storage, pools, spas and saunas; group (h) welding machines; group (i) X-ray equipment; group (j) other equipment by assessment. The ElecAS calculator labels every input with its Appendix C group letter.
Are lifts assessed as motors under Table C2?: No. Lifts are their own load group (e) and are assessed at 125% of the largest lift motor, plus 75% of the next largest, plus 50% of the remaining lift motors, in both columns. Ordinary motors (fans, pumps, compressors) are group (d), which uses full load of the highest-rated motor plus 50% of the remainder in Column 2, or plus 75% of the second highest and 50% of the remainder in Column 3.
Can I use Table C2 for a single-tenant office fit-out?: Yes. Table C2 is the correct table for any non-domestic installation including a single office tenancy, which is a Column 3 occupancy. Enter the connected load per group and the calculator applies the published Column 3 expressions.
Does Table C2 cover EV charging stations?: Yes. Charging equipment associated with electric vehicles is load group (c)(ii) of Table C2, assessed as the full connected load of the highest-rated unit plus 75% of the full load of the remainder, in both Column 2 and Column 3. The ElecAS calculator keeps EV chargers as their own line so the charging contribution to the consumer mains demand is visible in the report.