Transcript 01 Performance Requirements

LSEGG307A
9080F
Theory Test 1
Theory Test 2
Assignments
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
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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
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AS/NZS 3000:2007
AS/NZS 3008 :1998
Calculator
Determining a Wiring
System for an Installation
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How it is going to be used
Local authority requirements
Cost
Time requirements
Site access
Appearance/Aesthetics
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Domestic
Multiple domestic
Commercial
Industrial
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Power requirements of each of the loads connected
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How the loads are used
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Flexibility
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Safety of Human Property and Livestock
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Not be too inconvenient if a fault occurs
Constant or Intermittent
Temperature,
Be able toHigh
be easily
worked
on and
tested Mechanical damage, etc
Humidity,
Corrosive
atmospheres,
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Compatible with the climate
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Not be overloaded
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Not have too much voltage drop
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Not be affected by the Environment/Atmosphere
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Power requirements of each of the loads connected
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How the loads are used
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Flexibility
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Safety of Human Property and Livestock
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Not be too inconvenient if a fault occurs
Temperature,
Be able toHigh
be easily
worked
on and
tested
Humidity,
Corrosive
atmospheres,
Mechanical damage, etc
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Compatible with the climate
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Not be overloaded
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Not have too much voltage drop
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Not be affected by the Environment/Atmosphere
AS/NZS 3000
1.6.1
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AS/NZS 3000 and other electrical standards
Local supply authority standards
Building codes
Fire ratings
Heritage orders etc
Appearance
Concealed or Surface
Speed of installation
Cost
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
Used extensively used in office partitions
Advantages
 Most service holes are pre punched and deburred/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?
Concrete slab = Deck work
MD conduit with Building wire
Why not TPS?
Cable Ladder/tray
Steel Conduit
Steel Wire Armour
SWA 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 3000
Clause 1.6.1
Different loads require different
tripping times
AS/NZS 3000
Clause 2.6.2.1
AS/NZS 3000
Clause 1.5.5.3
How many? What size?
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The current required by each load
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The nature & usage of each load
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Economics
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The smaller the cable the cheaper
Flexibility of the installation
To major factors that have to be considered
 The power requirement of the load
 How the load is used
P  VI cos
P  3VI cos 
If used for more than 15 minutes it is
considered an “Extended Period”
Circuit requirements for a 4.8kW 230 Volt HWS
Maximum current =
P 4800
I 
 20A
V
230
Will 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
Are the lights likely to be all operating at the same time?
60
 45  11.7A
230
Protection will eventually trip.
2 Circuits are required
Commercial installation
Containing 45 x 60W light fittings
Are the lights likely to be all operating at the same time?
60
 45  11.7A
230
Protection will eventually trip.
2 Circuits are required
Domestic installation
Are the lights likely to be all operating at the same time?
60
 45  11.7A
230
Would the protection trip if all the
lights were
on for3000
a short period?
AS/NZS
Clause
2.5.3.1if all the lights
Would the cable
be damaged
were on for a short period?
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
AS/NZS 3000
Table 3.3
Table 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 3000
AS/NZS 3000
Clause 1.6.3
Clause 2.2.2
By:
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Calculation
Assessment
Measurement
Limitation
Calculation Using:
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Appendix C
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HB 301
15 minutes = “Extended Period”
AS/NZS 3000
Must be negotiated with user
Clause 1.6.1 (b)
Consumer & Sub-main size can be determined by sum of the
individual outgoing protection devices
82A
10A 16A 16A 20A
20A
Maximum Demand Value
AMPS
Protection
Requirements
Installation Type
Cable Size
Length of Run
Voltage Drop
Fault Loop
Fault Level