Electrical Calculations Software

# Maximum Demand Tables

## After diversity maximum demand

Under normal operating conditions not all the individual electrical equipment of an installation will operate at full load and simultaneously.  Therefore the total circuit current is estimated using diversity factors and is often described as the ‘after diversity maximum demand’.

The diversity factors applicable for a given circuit in an installation depend on the type of installation (i.e. residential, commercial, industrial) and several other factors.

Diversity factors for typical installations and usual equipment loads are provided in the Standards such as from the Australian Wiring Rules AS/NZS 3000.  See below.

A table for calculating energy demand for non-domestic installations is also below.

Disclaimer:  No responsibility is assumed for the accuracy of the Tables below.  Further, there are additional notes to these tables which are not included.

Table C1 Maximum Demand- Single and Multiple Domestic Electrical Installations

LoadSingle domestic electrical installation or individual living unit per phase Blocks of living units
2 to 5 living units per phase6 to 20 living units per phase21 or more living units per phase
A. Lighting
(i). Except (ii) and load group H below
3 A for 1 to 20 points + 2 A for each additional 20 points or part thereof6 A5 A + 0.25 A per living unit0.5 A per living unit
(ii). Outdoor lighting exceeding a total of 1000 W75% connected loadNo assessment for the purpose of maximum demand
B.
(i). Socket-outlets not exceeding 10 A Permanently connected electrical equipment not exceeding 10 A and not included in other load groups
10 A for 1 to 20 points + 5 A for each additional 20 points or part thereof10 A + 5 A per living unit15 A + 3.75 A per living unit50 A + 1.9 A per living unit
(ii). Where the electrical installation includes one or more 15 A socket-outlets, other than socket-outlets provided to supply electrical equipment set out in groups C, D, E, F, G, and L 10 A
(iii). Where the electrical installation includes one or more 20 A socket-outlets other than socket-outlets provided to supply electrical equipment set out in groups C, D, E, F, G, and L 15 A
C. Ranges, cooking appliances, laundry equipment or socket-outlets rated at more than 10 A for the connection thereof 50% connection load15 A2.8 A per living unit
D. Fixed space heating or airconditioning equipment, saunas or socket-outlets rated at more than 10 A for the connection thereof 75% connected load75% connected load75% connected load
E. Instantaneous water heaters 33.3% connected load6 A per living unit100 A + 0.8 A per living unit
F. Storage water heaters Full-load current6 A per living unit100 A + 0.8 A per living unit
G. Spa and swimming pool heaters75% of the largest spa, plus 75% of the largest swimming pool, plus 25% of the remainder
H. Communal lighting Not applicableFull connected load
I. Socket-outlets not included in groups J and M below Permanently connected electrical equipment not exceeding 10 ANot applicable2 A per point, up to a maximum of 15 A
J. Appliances rated at more than 10 A and socket-outlets for the connection thereof-
(i). Clothesdryers, water heaters, self-heating washing machines, wash boilers
(ii). Fixed space heating, airconditioning equipment, saunas Not applicable75% connected load
(iii). Spa and swimming pool heatersNot applicable 75% of the largest spa plus 75% of the largest swimming pool, plus 25% of the remainder
K. LiftsIn accordance with Paragraph C2.4.1 and Table C2In accordance with Paragraph C2.4.1 and Table C2, for determination of size of submains
L. MotorsIn accordance with Paragraph C2.4.1 and Table C2, Column 2In accordance with Paragraph C2.4.1 and Table C2, Column 2
M. Appliances, including socket-outlets other than those set out in groups A to L above, e.g. pottery kilns, welding machines, radio transmitters, X-ray equipment and the likeConnected load 5 A or less: No assessment for purpose of maximum demandConnected load 10 A or less: No assessment for purpose of maximum deman
Connected load over 5 A: By assessmentConnected load over 10 A: By assessment

Table C2 Maximum Demand Non-Domestic Electrical Installations

Load groupResidential institutions, hotels, boarding houses, hospitals, accommodation houses, motelsFactories, shops, stores, offices, business premises, schools and churches
B.
(i) Socket-outlets not exceeding 10 A other than those in B (ii)
1000 W for first outlet plus 400 W for each additional outlet1000 W for first outlet plus 750 W for each additional outlet
(ii) Socket-outlets not exceeding 10 A in buildings or portions of buildings provided with permanently installed heating and cooling equipment or both1000 W for first socket-outlet, plus 100 W for each additional outlet
(iii) Socket-outlets exceeding 10 AFull current rating of highest rated socket-outlet, plus 50% of full current rating of remainderFull current rating of highest rated socket-outlet, plus 75% of full current rating of remainder
C. Appliances for cooking, heating and cooling, including instantaneous water heaters, but not appliances included in groups D and J belowFull current rating of highest rated socket-outlet, plus 50% of full current rating of remainderFull current rating of highest rated socket-outlet, plus 75% of full current rating of remainder
D. Motors other than in E and F belowFull current rating of highest rated socket-outlet, plus 50% of full current rating of remainderFull load of highest rated motor, plus 75% of full load of second highest rated motor, plus 50% of full load of remainder
E. Lifts(i) Largest lift motor _ 125% full load
(ii) Next largest lift motor _ 75% full load
(iii) Remaining lift motors _ 50% full load
For the purpose of this load group, the full-load current of a lift motor shall mean the current taken from the supply when lifting maximum rated load at maximum rated speed
F. Fuel dispensing units(i) Motors : First motor _ full load
Second Motor _ 50% full load
G. Swimming pools, spas, saunas, thermal storage heaters including water heaters, space heaters, and similar arrangementsFull-load current
H. Welding machinesIn accordance with Paragraph C2.5.2, taking into account power factor correction
J. X-ray equipment50% of the full load of the largest x-ray unit, additional units being ignored
K. Other equipment not covered by load groups aboveBy assessment

Table C3 Maximum Demand – Energy Demand Method for non-Domestic Installations

Type of occupancyEnergy demand
Range, VA/m2Average, VA/m2
OfficesLight and Power
Air conditioning
-cooling
-reverse cycle
-zonal reheat
-variable volume
40-60

30-40
20-30
40-60
20
50

35
25
50
20
CarparksOpen Air
Basement
0-10
10-20
5
15
Retail ShopsLight and Power
Air conditioning
40-100
20-40
70
30
WarehousesLight and Power
Ventilation
Special Equipment
5-15
5
10
5

Light industrialLight and Power
Ventilation
Air conditioning
Special Equipment
10-20
10-20
30-50