1. ELECTRICAL INSTALLATION PLANNING
LSEGG307A
9080F

2. Assessments Theory Test 1 Theory Test 2 Assignments Final Examination
10%
20%
60%

3. Lesson Content Protection against harmful effects Correct functioning
Supply characteristics
Determining Maximum demand
Voltage drop limitations
Arrangement into circuits
External Factors
Protection against
Integrity of fire rated construction
Direct contact
Indirect contact
Thermal effects
Overcurrent
Faults
Mechanical movement

4. SELECTION OF CABLE & EQUIPMENT WITH REGARD TO:
Type of structure/location & what it is used for
Number & type of circuits
Current carrying capacity of the cable
Voltage drop
Fault loop impedance
Maximum demand
Fault levels
Metering
Damp situations
Voltage levels

5. What you will require each week
AS/NZS 3000:2007
AS/NZS 3008 :1998
Calculator

6. THIS SUBJECT WILL BE EXAMINED IN THE CAPSTONE TEST

7. Determining a Wiring System for an Installation
Lesson 1
Determining a Wiring System for an Installation

8. What determines the type of building structure chosen?
How it is going to be used
Local authority requirements
Cost
Time requirements
Site access
Appearance/Aesthetics
Domestic
Multiple domestic
Commercial
Industrial

9. What Determines The Type of Cable System Chosen?
Power requirements of each of the loads connected
How the loads are used
Flexibility
Safety of Human Property and Livestock
Not be too inconvenient if a fault occurs
Be able to be easily worked on and tested
Compatible with the climate
Not be overloaded
Not have too much voltage drop
Not be affected by the Environment/Atmosphere
Constant or Intermittent
Temperature, High Humidity, Corrosive atmospheres, Mechanical damage, etc

10. What Determines The Type of Cable System Chosen?
Power requirements of each of the loads connected
How the loads are used
Flexibility
Safety of Human Property and Livestock
Not be too inconvenient if a fault occurs
Be able to be easily worked on and tested
Compatible with the climate
Not be overloaded
Not have too much voltage drop
Not be affected by the Environment/Atmosphere
Temperature, High Humidity, Corrosive atmospheres, Mechanical damage, etc
AS/NZS 3000
1.6.1

11. Other Factors That An Electrician Has To Consider/Abide by :-
AS/NZS 3000 and other electrical standards
Local supply authority standards
Building codes
Fire ratings
Heritage orders etc
Appearance
Speed of installation
Cost
Concealed or Surface
Materials & Labor

12. Timber Frame Advantages Disadvantages
Insulator, so earthing not a problem
Material relatively soft so cable damage not a major problem
Disadvantages
Drilling in structural members is limited
All service holes have to be drilled on site

13. Used extensively used in office partitions
Steel Frame
Used extensively used in office partitions
Advantages
Most service holes are pre punched and de-burred/flanged
Very lightweight construction.
Disadvantages
Earthing of the frame has to be considered
Additional holes made must be de-burred

14. Timber & Steel Frame
TPS inside frame is most commonly used
Why?

15. Full Brick & Concrete Slab
Concrete slab = Deck work
MD conduit with Building wire
Why not TPS?

16. Industrial Installations
Cable Ladder/tray
Steel Conduit
Steel Wire Armour
SWA Cable is more Expensive than Steel Conduit so why is more commonly used?
MIMS

17. Exercise 1

18. Planning & Arranging Circuits
Why do we break the installation up into circuits?
Why not put all the loads on one or two circuits?

19. Circuits How many? What size?
Reduce the inconvenience in the event of a fault
Safe inspection, testing & maintenance
Unwanted nucence tripping
Fault protection.
Different loads require different tripping times
AS/NZS 3000
Clause 1.6.1
AS/NZS 3000
Clause
AS/NZS 3000
Clause

20. Circuits How many? What size? The current required by each load
The nature & usage of each load
Economics
Flexibility of the installation
The smaller the cable the cheaper

21. If used for more than 15 minutes it is considered an “Extended Period”
Loading Of The Circuit
To major factors that have to be considered
The power requirement of the load
How the load is used
If used for more than 15 minutes it is considered an “Extended Period”

22. Example 1 20A Circuit requirements for a 4.8kW 230 Volt HWS
Maximum current =
20A
Will it be used for extended periods?
On its own circuit?
Or with other loads on one circuit?

23. Cheaper to make two circuits
Example 2
Circuit requirements for two 4.8kW 230 Volt HWS
4mm2 T&E = $2.50/m
2.5mm2 T&E = $0.85/m
Cheaper to make two circuits

24. Protection will eventually trip.
Example 3
Commercial installation
Containing 45 x 60W light fittings
Are the lights likely to be all operating at the same time?
11.7A
Protection will eventually trip.
2 Circuits are required

25. Protection will eventually trip.
Example 3
Commercial installation
Containing 45 x 60W light fittings
Are the lights likely to be all operating at the same time?
11.7A
Protection will eventually trip.
2 Circuits are required

26. Domestic installation
Example 3
Domestic installation
Are the lights likely to be all operating at the same time?
11.7A
Would the protection trip if all the lights were on for a short period?
AS/NZS 3000
Clause
Would the cable be damaged if all the lights were on for a short period?

27. Socket Outlets
Do we put more than 1 double socket outlet on a single circuit?
What is the minimum size cable that we can generally use?
AS/NZS 3000
Table 3.3
AS/NZS 3000
Table C8

28. Known Loads Connected To Socket Outlets
What type of loads are in the kitchen and laundry of a house?
Would you put all these loads on the one circuit?

29. Exercise 2

30. The Current that is normal expected by this type of load
Maximum Demand
The Current that is normal expected by this type of load
“Average Current”
AS/NZS 3000
Clause 1.6.3
AS/NZS 3000
Clause 2.2.2

31. Maximum Demand By: Calculation Assessment Measurement Limitation
Calculation Using:
Appendix C
HB 301
15 minutes = “Extended Period”
AS/NZS 3000
Clause (b)
Must be negotiated with user
Consumer & Sub-main size can be determined by sum of the individual outgoing protection devices
82A
10A
16A
16A
20A
20A

32. Protection Requirements
Maximum Demand
Maximum Demand Value
AMPS
Installation Type
Protection Requirements
Cable Size
Length of Run
Voltage Drop
Fault Loop
Fault Level