AT5 Flashcards
Periodic intervals for testing electrical equipment on construction sites can be found in which Australian standard?
AS/NZS 3012 table 6 or clause 3.4.2
You are carrying out a periodic visual test on single phase portable electrical equipment. List three main points you would check in relation to the flexible cord. Also list the relevant AS/NZS document and clause
- The inner cores of flexible cords are not exposed or twisted
- The external sheaths are not cut, abraded, twisted, or damaged to such an extent that the insulation of the inner cores is visible
- Unprotected conductors or the use of banding insulation tape are not in evidence
Where there is more than one switchboard on a construction site, what are the requirements for identification of the source of supply? Also list the relevant AS/NZS 3012
Marking shall be provided to distinguish one switchboard from another
Clause 2.3.2.1 f
Match the categories to the statements for construction and demolition
A) all sub circuits shall have RCD’s
B) if of the festooned type shall be supported above any floor
C) circuit breakers for these circuits shall be tested an tagged to prevent inadvertent isolation
D) shall be readily accessible and protected from damage during construction work
E) shall not be rated less than 10A
F) when supported by a catenary shall be stranded or flexible
Switchboards = ?
Protection of circuits = ?
Construction wiring = ?
Lighting = ?
Socket outlets = ?
Lift circuits = ?
Switchboards = D
Protection of circuits = A
Construction wiring = F
Lighting = B
Socket outlets = E
Lift circuits = C
What is an unprotected consumers mains?
What clause number outlines methods of protection?
A = consumer mains that does not have short circuit protection (2.5.1.2)
B = AS/NZS 3000 clause: 3.9.7.1.2 for methods of protection
For an unprotected consumers mains, what is the minimum size the switchboard bonding must be? List the relevant AS/NZS 3000 clause
Same size as the main neutral
AS/NZS 3000 clause: 5.5.3.5
When terminating a cable for connection what are the requirements for preparation of the conductor?
The insulation shall not be removed any further than is necessary to make the connection
AS/NZS 3000: 3.7.2.2
Match the common application to the cable type
Flat thermoplastic sheathed = ?
Circular thermoplastic sheathed = ?
Steel wire armoured = ?
Fire rated = ?
Flexible = ?
A = extension cord
B = thermal combustion sensor
C = mains cable buried direct
D = house light and power
E = 400v motor supply
Flat thermoplastic sheathed = D
Circular thermoplastic sheathed = E
Steel wire armoured = C
Fire rated = B
Flexible = A
Identify two safe working procedures when connecting or testing transformers. Select two responses
A = Transformers must have a certificate of compliance
B = a cat 2 meter is acceptable to use to test transformers
C = never change taps when energised
D = always consider the transformer is energised until disconnected
C = never change taps when energised
D = always consider the transformer is energised until disconnected
What is one requirement for housing current transformers for metering? Also list the relevant QECM clause
A = In a separate dedicated metering chamber
B = at least 50mm from another service opening
AS/NZS 3000: 3.9.9.3 a i
How must a switchboard be identified?
Legibly and permanently marked ‘main switchboard’
AS/NZS 3000: 2.10.2.4
What is the minimum clearance around a switchboard?
600mm
In general terms where should a main switchboard be located?
Readily accessible with easy access of an entrance to a building
AS/NZS 3000: 2.10.2.3
What clause in the AS/NZS 3000 outlines restricted locations for any switchboards
AS/NZS 3000: 2.10.2.5
If two or more circuit breakers are mounted in a row in a switchboard, how should they be oriented?
Each shall operate in the open position in the same orientation
How shall switchboards be constructed with regards to live parts? List the AS/NZS 3000 clause
Shall be arranged so that basic protection is provided by enclosures
AS/NZS 3000: 2.10.3.1
What size switchboard is required to have protection against internal arc fault currents
800A or greater
AS/NZS 3000: 2.5.5.1
What are the general requirements for installing and routing cables?
In accordance with generally accepted principles of safe and sound practice, using methods of protection against mechanical and electrical failure
Identify the correct order for commissioning electrical equipment. Complete with 1 being first and 5 being last
Check equipment can manage given load = ?
Check supply voltage = ?
Check parameters of any controls = ?
Check polarity and phase rotation = ?
Check equipment functions as intended = ?
Check equipment can manage given load = 3
Check supply voltage = 1
Check parameters of any controls = 5
Check polarity and phase rotation = 2
Check equipment functions as intended = 4
What is the mandatory requirement that must be performed prior or in conjunction with testing an installation?
Visual Inspection
AS/NZS 3000 8.2.1 or 1.8
List the mandatory tests required to test a low voltage installation?
Earth continuity
Insulation resistance
Polarity and correct connections
Earth fault loop impedance
RCD’s
AS/NZS 3000: 8.3.3.1
Harmonics can affect a cables current capacity, name two appliances that can cause this
Fluorescent lighting
Computers
Soft starters
Variable speed drives
Other electronic devices
AS/NZS3000: 3.5.2b i
What are the general requirements for fixing wiring systems in a fixed position
By using suitable clips, saddles or clamps or by means that will not damage the wiring system
Match the typical cable routes to the following by writing the correct letter
A - commercial building
B - residential
C - solar array
Ceiling joists and beams = ?
risers and ceiling catenary = ?
Framework and supports = ?
Ceiling joists and beams = B
risers and ceiling catenary = A
Framework and supports = C
Select the requirements for preparation and fitting of local supply authority
Holes drilled to QECM templates
Contractor mounts the principal supply meter
Neutral for metering is wired direct from main neutral link
Cables are minimum 150mm in length
Holes drilled to QECM templates
Cables are minimum 150mm in length
What is one restriction on the installation and use of an auto transformer
Shall not be used to supply electrical equipment, including circuits wiring, having a voltage rating higher than the highest input or output voltage of the transformer
AS/NZS 3000: 4.14.4
