LSEGG307A9080F

Theory Test 1Theory Test 2Assignments

Final Examination

10%20%10%60%

• 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

• 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

AS/NZS 3000:2007 AS/NZS 3008 :1998 Calculator

Determining a Determining a Wiring System for Wiring System for

an Installationan Installation

How it is going to be used

Local authority requirements

Cost

Time requirements

Site access

Appearance/Aesthetics

• Domestic• Multiple

domestic• Commercial• Industrial

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

Temperature, High Humidity, Corrosive atmospheres, Mechanical damage, etc

AS/NZS 30001.6.1

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

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

Advantages 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

Advantages

Used extensively used in office partitions

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

TPS inside frame is most commonly used

Why? Why?

Concrete slab = Deck work

MD conduit with Building wire

Why not TPS? Why not TPS?

Cable Ladder/traySteel Conduit

Steel Wire ArmourSWA Cable is more Expensive than Steel Conduit so why is

more commonly used?MIMS

Why do we break the installation up into

circuits?Why not put all the loads on one or two circuits?

How many? What size?

Reduce the inconvenience in the event of a fault

Safe inspection, testing & maintenance

Unwanted nucence tripping

Fault protection.

AS/NZS 3000Clause 1.6.1

Different loads require different tripping times

AS/NZS 3000Clause 2.6.2.1 AS/NZS 3000

Clause 1.5.5.3

How many? What size?

The current required by each load

The nature & usage of each load

Economics

Flexibility of the installationThe smaller the cable the cheaper

cosVIP

To major factors that have to be considered

The power requirement of the load

How the load is used

cosVI3PIf used for more than 15 minutes it is

considered an “Extended Period”

Circuit requirements for a 4.8kW 230 Volt HWS

Maximum current = 230

4800

V

PI 20

AWill it be used for extended periods?

On its own circuit?

Or with other loads on one circuit?

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

Commercial installation Containing 45 x 60W light fittings

45230

60

Are the lights likely to be all operating at the same time?

11.7A

Protection will eventually trip.

2 Circuits are required

Commercial installation Containing 45 x 60W light fittings

45230

60

Are the lights likely to be all operating at the same time?

11.7A

Protection will eventually trip.

2 Circuits are required

45230

60Are the lights likely to be all operating at the same time?

11.7A

Domestic installation

Would the protection trip if all the lights were on for a short

period?Would the cable be damaged if all

the lights were on for a short period?

AS/NZS 3000Clause 2.5.3.1

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 3000Table 3.3

AS/NZS 3000Table C8

What type of loads are in the kitchen and laundry of a

house?

Would you put all these loads on the one circuit?

The Current that is normal expected by this

type of load“Average Current”

AS/NZS 3000Clause 1.6.3

AS/NZS 3000Clause 2.2.2

Calculation Using:

Appendix C

HB 301

By:•Calculation•Assessment•Measurement•Limitation

15 minutes = “Extended Period”

Consumer & Sub-main size can be determined by sum of the individual outgoing protection devices

10A 16A 16A 20A 20A

82A

AS/NZS 3000Clause 1.6.1 (b) Must be negotiated with user

Maximum Demand Value

AMPS

Cable Size

Installation Type Protection Requirements

Voltage Drop

Length of Run

Fault Loop Fault Level