### ELECTRICAL INSTALLATION PLANNING

```LSEGG307A
9080F
• Describe the acceptable methods for
determining the maximum demand on an
installation’s consumer’s mains.
• Calculate the maximum demand for the
consumer's mains for given installations up to
400 A per phase.
What is Maximum Demand?
MD
Is the “Maximum continuous current that flows in a
circuit for a period of 15 minutes or longer”
AS/NZS 3000
1.6.3
Why not just put a cable size in, that will handle the
current rating for the maximum current rating of the
appliance?
What is Maximum Demand?
Domestic stove rated at 5kW
Max current = 22A
Min cable size = 6mm2
By calculation
Max current = 16A
Min cable size = 2.5mm2
AS/NZS 3000
Table C4
AS/NZS 3000
2.2.2.
Calculation
 Assessment
 Measurement
 Limitation

“If the measured current is larger than any of the
listed methods, then the MD is considered the
measured value”
AS/NZS 3000
Clause 2.2.2 (d)
“… may be the ….sum of the current settings of
the circuit breakers protecting the associated
final sub-circuits….”
10+10+16+16+32 =
By Calculation
16mm2
84 Amps
36 Amps
MD = ?
10mm2
2.5mm2
20 metres
10A
L1
46 metres
10A
L2
16A
P1
16A
P2
Domestic House
32A
Stove



Domestic
Table C1
Non-domestic
Table C2
Non- domestic Energy Demand
Table C3
Single House
Table C1 Column 2
Lighting
Batten holder = 1 light point
25 lighting points = 1 -20 = 3 A
21 -25 = 2 A
5A
Single House
Table C1 Column 2
Lighting
Chandelier or Multi-globe fitting = Number of points =
Number of globes
= 3 points
Single House
Table C1 Column 2
Lighting
Power points above 2.3 m for lighting = 1 point
Note “e”
Exhaust fans below 150W = 1 point
Single House
Table C1 Column 2
Lighting
Track lights = Every metre =
Note “d”
2 x 2.6 metres track light =
2 points
5 points per track = 10 points
Single House
Table C1 Column 2
Lighting
IXL Tastics, Heat lamps etc
Not regarded as “Lighting”
Fixed Space Heating
Single House
Table C1 Column 2
Lighting
Outside Lighting
Floodlighting, Swimming
Not lighting around
Pool, Tennis courts, etc
house walls
If total bigger
If less than
than 1000W
1000W
A house consists of the following:
36 light fittings, 3 consisting of 3 lamp combinations
3 bathroom exhaust fans
2 x 750W heat lamp, fan, light combinations
3 x 2metre track lights
12 wall lights around the veranda
6 x 100W bollard lights on driveway
6 x 400W metal halide flood lights for pool
6 x 100 = 600
6 x 400 = 2400
3000 W
230V
Determine the lighting load in Amps
Assume to be <150W
Ai
Ai
D
Ai
Ai
Aii
Aii
33 + (3 x 3) = 42P
3P
3 x 2 x 2 = 12P
12P
13.04A
A house consists of the following:
36 light fittings, 3 consisting of 3 lamp combinations
3 bathroom exhaust fans
2 x 750W heat lamp, fan, light combinations
3 x 2metre track lights
12 wall lights around the veranda
6 x 100W bollard lights on driveway
6 x 400W metal halide flood lights for pool
42P
3P
12P
12P
69P
1 – 20 =
21 – 40 =
41 – 60 =
61 – 69 =
Ai
Ai
D
Ai
Ai
Aii
Aii
33 + (3 x 3) = 42P
3P
3 x 2 x 2 = 12P
12P
13.04A
3A
2A
2A
2A
9A + 13.04A =
22.04A
Broken up evenly
36 light fittings
3
A B C
12 Fittings / 3A 3A 3A
Should indicate how it is to be broken up
across the three phases
NOT
36 light fittings = 3A + 2A = 5A
3
A B C
1.6 1.6 1.6
A house consists of the following:
Broken up evenly over 3 Phases
36 light fittings, 3 consisting of 3 lamp combinations
3 bathroom exhaust fans
Divide by 3
2 x 750W heat lamp, fan, light combinations
3 x 2metre track lights
12 wall lights around the veranda
6 x 100W bollard lights on driveway
6 x 400W metal halide flood lights for pool
14P
1P
4P
4P
23P
Ai
Ai
D
Ai
Ai
Aii
Aii
11 + (1 x 3) = 14P
1P
1 x 2 x 2 = 4P
4P
4.35A
1 – 20 = 3A
21 – 23 = 2A
5A + 4.35A =
9.35A /
Power Points
Double Power Points
36 Double Power Points
6 Single power points
Notes
h
36 x 2 =72P
6P
1 – 20 =
78P
21 – 40=
41 – 60 =
61 – 78 =
10A
5A
5A
5A
25A
Power Points
Notes
h
Double Power Points
36 Double Power Points
6 Single power points
36 x 2 =72P
6P
AND
Other Direct Wired
Equipment that is <10A
• Air conditioners
• Cook tops
• Water heaters
78P
1 – 20 =
21 – 40=
41 – 60 =
61 – 78 =
10A
5A
5A
5A
25A
Power Points
NOT
15 A Power Points
Other Equipment that is
below
C
D
E&F
G
Ranges, Laundry equipment
Fixed Space Heating or cooling equipment
Water Heaters
Spa & Swimming Pool Heaters
15 A Power Points suppling this equipment is covered
A house consists of the following:
20 Double power points
8 Single power points
8A swimming pool pump
34 x 15A power points
12A Air-conditioner supplied via a 15A power point
14A Pool heater direct wired
Bi
Bi
Bi
Bii
D
G
Determine the Power point load in Amps
20 x 2 = 40P
8P
1P
10A
-
A house consists of the following:
20 Double power points
8 Single power points
8A swimming pool pump
3 x 15A power points
12A Air-conditioner supplied via a 15A power point
14A Pool heater direct wired
40P
8P
1P
49P
Bi
Bi
Bi
Bii
D
G
1 – 20 = 10A
21 – 40 = 5A
41 – 49 = 5A
20A + 10A =
30A
20 x 2 = 40P
8P
1P
10A
-
•
•
•
•
Cook tops
Wall ovens
Washing machines
Clothes driers
Must be over 10A
If supplied via a power point
That power point is NOT included in Bi, Bii or Biii
An installation has:
2.3 kW Cook top
4 kW Wall oven
6.3 kW of Load Group C
(6300/230) x 0.5 = 13.7A
•
•
•
•
IXL Tastics Heat lamps
Air conditioners
Heaters
Under floor heating
Must be over 10A
If supplied via a power point
That power point is NOT included in Bi, Bii or Biii
If reverse cycle Air-conditioner is used only the
highest system is to be taken into account
Unless it is multi zone, when both heating and
cooling could operate simultaneously
Water Heaters
15 litre heater
with a 2.4kW element
2400/15 =
160 W/L
• Instantaneous
• Quick recovery
If greater than 100W/L
300 litre heater
with a 2.4kW element
2400/300 =
8 W/L
• Storage
• Off peak
A house consists of the following:
Ai
Ai
Bi
Bi
C
D
F
41 x 50 W down lights
2 x 60 W exhaust fans
4 x Single 10 A socket outlets
22 x Double 10 A socket outlets
1 x 10kW range
1 x Permanently connected air conditioner (full load current of 13 A)
1 x 4.6 kW continuous HWS
A house consists of the following:
Ai
Ai
Bi
Bi
C
D
F
41 x 50 W down lights
43P 3 + 2 + 2 =
2 x 60 W exhaust fans
4 x Single 10 A socket outlets
22 x Double 10 A socket outlets
1 x 10kW range
1 x Permanently connected air conditioner (full load current of 13 A)
1 x 4.6 kW continuous HWS
7A
A house consists of the following:
Ai
Ai
Bi
Bi
C
D
F
41 x 50 W down lights
2 x 60 W exhaust fans
4 x Single 10 A socket outlets
44 + 4 = 48P 10 + 5 + 5 =
22 x Double 10 A socket outlets 44P
1 x 10kW range
1 x Permanently connected air conditioner (full load current of 13 A)
1 x 4.6 kW continuous HWS
7A
20A
A house consists of the following:
Ai
Ai
Bi
Bi
C
D
F
41 x 50 W down lights
2 x 60 W exhaust fans
4 x Single 10 A socket outlets
22 x Double 10 A socket outlets
1 x 10kW range (10000/230) x 0.5 =
1 x Permanently connected air conditioner (full load current of 13 A)
1 x 4.6 kW continuous HWS
7A
20A
21.7A
A house consists of the following:
Ai
Ai
Bi
Bi
C
D
F
41 x 50 W down lights
2 x 60 W exhaust fans
4 x Single 10 A socket outlets
22 x Double 10 A socket outlets
1 x 10kW range
1 x Permanently connected air conditioner (full load current of 13 A)
1 x 4.6 kW continuous HWS
13 x 0.75 =
7A
20A
21.7A
9.75A
A house consists of the following:
Ai
Ai
Bi
Bi
C
D
F
41 x 50 W down lights
2 x 60 W exhaust fans
4 x Single 10 A socket outlets
22 x Double 10 A socket outlets
1 x 10kW range
1 x Permanently connected air conditioner (full load current of 13 A)
1 x 4.6 kW continuous HWS 4600/230 =
7A
20A
21.7A
9.75A
20A
A house consists of the following:
Ai
Ai
Bi
Bi
C
D
F
41 x 50 W down lights
2 x 60 W exhaust fans
4 x Single 10 A socket outlets
22 x Double 10 A socket outlets
1 x 10kW range
1 x Permanently connected air conditioner (full load current of 13 A)
1 x 4.6 kW continuous HWS
7A
20A
21.7A
9.75A
20A
78.45A
Not all single phase loads will break up evenly over three phases
But the phases must not be unbalanced by more than
25A
NSW S&IR
Clause 1.10.3
A house consists of the following:
Ai A 30 x Light points + 2 x Exhaust fans
Ai B 18 x Lights
Aii C 6 x 400W mercury vapour flood lights
Bi A 15 x Double power points (p/p)
Bi B 10 x Single p/p & 15 x Double p/p
Bii C 3 x 15A Single p/p
C A 1 x 4.1kW wall oven
C B 1 x 4.6kW cook top
F C 1 x 3.6kW heat pump HWS
A
D B
C
1 x 5.7kW 3 Air conditioner
A house consists of the following:
Ai A 30 x Light points + 2 x Exhaust fans 32P
Ai B 18 x Lights
3+2A =
5A
3A
18P
Aii C 6 x 400W mercury vapour flood lights ((6x400)230)x0.75 =
Bi A 15 x Double power points (p/p)
Bi B 10 x Single p/p & 15 x Double p/p
30P
10+30P
10+5A =
7.83A
15A
20A
10+5A =
Bii C 3 x 15A Single p/p
C A 1 x 4.1kW wall oven
C B 1 x 4.6kW cook top
F C 1 x 3.6kW heat pump HWS
10A
(4100230)x0.5 =
C
10A
(4600230)x0.5 =
15.65A
3600230 =
A
D B
8.91A
6.17A
1 x 5.7kW 3 Air conditioner
(5700x0.75)(√3 x400) =
6.17A
6.17A
35.1A 39.2A 40.2A
Submains to individual units
Unit 1
MSB
Unit 2
Unit 3
Columns 3, 4 or 5
Column 2
 How many units are there?
 How are they spread across the 3 phases?
6 Units
3
= 2 Units / Phase Use Colum 3
18 Units
3
66 Units
3
= 6 Units / Phase Use Colum 4
= 22 Units / Phase Use Colum 5
A house consists of the following:
Ai 26 x Light points
26 + 4 = 30P
3A + 2A = 5A
Ai 2 metres of light track 2 x 2 = 4P
Aii 2 x 750W flood lights 1500W (1500W/230V)x0.75
10A + 5A + 5A = 20A
Bi 26 x Double 10 A socket outlets 26 x 2 = 52P
Bi 5 x Single 10 A socket outlets
4.9A
52 + 5 = 57P
Bii 1 x 15A Single socket outlet
10A
C 1 x 5.6kW wall oven / cook top (5600W/230V)x0.5
12.2A
D 1 x 3.6kW air conditioner (3600W/230V)x0.75
11.7A
F 1 x 2.4kW storage HWS (Heat pump) (2400W/230V)
10.4A
74.2A
9 Units consists of the following:
9 Units
3
= 3 Units / Phase
Use Colum 3
Ai 26 x Light points
6A
Ai 2 metres of light track
Aii 2 x 750W flood lights Not counted
Bi 26 x Double 10 A socket outlets
10A + (5A x 3) = 25A
Bi 5 x Single 10 A socket outlets
Bii 1 x 15A Single socket outlet
10A
C 1 x 5.6kW wall oven / cook top
15A
D 1 x 3.6kW air conditioner (3600W/230V) x 0.75 x 3
F 1 x 2.4kW storage HWS (Heat pump)
35.2A
6A x 3 = 18A
109A
30 Units consists of the following:
30 Units
3
= 10 Units / Phase Use Colum 4
Ai 26 x Light points
5A + (0.25A x 10) = 7.5A
Ai 2 metres of light track
Aii 2 x 750W flood lights Not counted
Bi 26 x Double 10 A socket outlets
15A + (3.75A x 10) = 52.5A
Bi 5 x Single 10 A socket outlets
Bii 1 x 15A Single socket outlet
C 1 x 5.6kW wall oven / cook top
D 1 x 3.6kW air conditioner (3600W/230V) x 0.75 x 10
F 1 x 2.4kW storage HWS (Heat pump)
10A
2.8A x 10 = 28A
117A
6A x 10 = 60A
275A
66 Units consists of the following:
66 Units
3
= 22 Units / Phase Use Colum 5
Ai 26 x Light points
0.5A x 22 = 11A
Ai 2 metres of light track
Aii 2 x 750W flood lights Not counted
Bi 26 x Double 10 A socket outlets
50A + (1.9A x 22) = 91.8A
Bi 5 x Single 10 A socket outlets
Bii 1 x 15A Single socket outlet
C 1 x 5.6kW wall oven / cook top
D 1 x 3.6kW air conditioner (3600W/230V) x 0.75 x 22
F 1 x 2.4kW storage HWS (Heat pump)
10A
2.8A x 22 = 61.6A
258A
100A + (0.8A x 22) =118A
550A
16 Units
3
A
5 Units
Col 3
= 5.33 Units / Phase
B
5 Units
Col 3
C
6 Units
Col 4
But the phases must not be unbalanced by more than 25A
NSW S&IR
Clause 1.10.3
16 Units consists of the following:
5 Units / A & B
Ai
26 x Light points
Bi
26 x Double 10 A socket outlets
Bi
5 x Single 10 A socket outlets
Use Colum 3
6A
10A + (5A x 5) =
35A
Bii 1 x 15A Single socket outlet
10A
C
1 x 5.6kW wall oven / cook top
15A
D
1 x 3.6kW air conditioner (3600W/230V) x 0.75 x 5
F
1 x 2.4kW storage HWS (Heat pump)
(2400230V) x 5 =
58.7A
52.2A
176.9A
16 Units consists of the following:
6 Units / C
Use Colum 4
5A + (0.25A x 6) =
Ai
26 x Light points
Bi
26 x Double 10 A socket outlets
Bi
5 x Single 10 A socket outlets
6.5A
15A + (3.75A x 6) = 37.5A
Bii 1 x 15A Single socket outlet
10A
C
1 x 5.6kW wall oven / cook top
D
1 x 3.6kW air conditioner
F
1 x 2.4kW storage HWS (Heat pump)
2.8A x 6 =
(3600230) x 0.75 x 6
16.8A
70.4A
6A x 6 =
36A
177.2A
16 Units
3
A
5 Units
Col 3
176.6A
= 5.33 Units / Phase
B
5 Units
Col 3
176.6A
C
6 Units
Col 4
177.2A
Loads that are used by all the unit dwellers
• Driveway/ parking lighting
• Stairwell lighting
• Power points for cleaners
• Lifts
• Swimming pool pumps
16 Units have a communal load consists of the following:
H 20 x 80 W bollard Lights
((20x80)230) + ((30x 60)230) =
14.78A
H 30 x light points
I
15 x Single 10 A socket outlets
2A x15= 30 but maximum of 15A
15A
Ji 1 x 3.6kW HWS for cleaners room (3600230) x 0.5 =
7.8A
Jii 1 x 3.6kW Air conditioner for lobby (3600230) x 0.75 =
15A
D 1 x 12A pool pump/filter
12A
E 1 x 15A lift motor
Table C2 Colum 2
15 x 1.25 =
18.75A
83.33A
These circuits could also be divided across three phases
In a Factory On each Phase
20 x 10A single power points

1000W +
19 x 750W = 15.25kW
15250 ÷ 230 = 66.3 Amps
In areas with air conditioning

20 x 10A single power points
1000W +
19 x 100W = 2.9kW
2900 ÷ 230 =12.6 Amps

5 x 10A 3 outlets
Treat as B(i)
1000W + 4 x 750W =
Per Phase
4kW
4000 ÷ 230 = 17.4 Amps


2 x 32A 3 outlets
5 x 20A 3 outlets
75% x 32A
32A +
24A +
75A =
Per Phase
75% x 20A x 5
131Amps
In Factories


2 x 30A 3 motors
3 x 15A 1 motors
75% x 30A
30A +
22.5A +
1 per phase
50% x 3 x 15A
22.5A = 75 Amps

AS/NZS 3000
C2.5.2.2 (b)
3 x 20A 3 Welders
Majority of welders only use 2 phases
B
A
W1
C
W2
Only 2 welders on
each phase
W3
20A + 20A = 40 Amps
Per Phase
Use for a ‘Ball Park’ figure in early planning stages.
Table based on a temperate climate
Office
Floor area = 850m2
Light/Power = 50 VA/m2
Reverse cycle AC =
25 VA/m2
75 VA/m2
63.750kVA
√3 x 400
=
x 850 = 63.750kVA
92 Amps/Phase
```