Evidence shall show that knowledge has been acquired of selecting wiring systems and cables for general electrical installations. All knowledge and skills detailed in this unit should be contextualised to current industry practices and technologies. KS01-EG107A Electrical installation — cable selection and co-ordination Evidence shall show an understanding of selecting cables and ensuring co-ordination between protection device and conductors in electrical installations that comply with the Wiring Rules, Selection of cables standards and Service Rules to an extent indicated by the following aspects: T1 Performance requirements - design and safety encompassing: harmful effects against which the design of an electrical installation must provide protection. performance standards of a correctly functioning electrical installation. supply characteristics that shall be considered when designing an electrical installation. acceptable methods for determining the maximum demand in consumer's mains and sub-mains. AS/NZS 3000 requirements limiting voltage drop in an installation. reason for dividing electrical installations into circuits and the factors that shall determine their number and type. typical external factors that may damage an electrical installation and that shall be considered in the installation design. methods for protecting persons and livestock against direct and indirect contact with conductive parts and the typical application of each. acceptable methods of protection against the risks of ignition of flammable materials and injury by burns from the thermal effects of current, in normal service. likely sources of unwanted voltages and the methods for dealing with this potential hazard. acceptable methods for protecting persons and livestock against injury and property against damage from the effects of over current. requirement for protection against fault current. requirement for protection against the harmful effects of faults between live parts of circuits supplied at different voltages. need for protection against injury from mechanical movement and how this may be achieved. features of 'fire rated construction' and how the integrity of the fire rating can be maintained in relation to electrical installation. T2 Final subcircuit arrangements encompassing: factors that shall be considered in determining the number and type of circuits required for an installation. daily and seasonal demand for lighting, power, heating and other loads in a given installation. number and types of circuits required or a particular installation. current requirements for given final subcircuits. layout/schedule of circuits for given installations. T3 Factors affecting the suitability of wiring systems encompassing: wiring systems typically used with various construction methods and particular environments. installation conditions that may affect the current-carrying capacity of cables. external influences that may affect the current-carrying capacity and/or may cause damage to the wiring system. AS/NZS 3000 requirements for selecting wiring systems for a range of circuits, installation conditions and construction methods into which the wiring system is to be installed. Note: Wiring systems include cable enclosures, underground wiring, aerial wiring, catenary support, emergency systems, busbar trunking and earth sheath return. T4 Maximum demand on consumer’s mains/submains encompassing: acceptable methods for determining the maximum demand on an installation’s consumer’s mains and submains. maximum demand for the consumer's mains for given installations up to 400 A per phase. maximum demand for given submains. T5 Cable selection based on current carrying capacity requirements encompassing: installation conditions for a range of wiring systems and applications. external influences that require the use of a derating factor. AS/NZS 3000 requirements for coordination of cables and protection devices. AS/NZS 3008 used to select conductor size based on the maximum current requirement for a given installation condition including any applicable derating factors. T6 Cable selection based on voltage drop requirements encompassing: AS/NZS 3000 requirements for maximum voltage drop in an installation. relevant tables in AS/NZS 3008 for unit values of voltage drop. calculation of the expected voltage drop in a given circuit. selecting cables to satisfy voltage drop requirements in addition to current carrying capacity requirements. T7 Cable selection based on fault loop impedance requirements encompassing: AS/NZS 3000 requirements for maximum fault loop impedance in an installation. relevant tables in AS/NZS 3008 to determine cable impedances. calculation of the expected fault loop impedance for a given circuit arrangement. selecting cables to satisfy fault loop impedance requirements in addition to current carrying capacity requirements and voltage drop requirements. T8 Selecting protection devices encompassing: acceptable methods of protection against indirect contact. AS/NZS 3000 requirements for selecting methods and devices to protect against indirect contact for a range of installation types and conditions. coordination between conductors and protection devices to ensures the protection of cables from over heating due to over current. possible injuries to persons and livestock from hazards due to a short circuit. AS/NZS 3000 requirements for selecting devices to protect against overload current for a range of circuits and loads. AS/NZS 3000 requirements for selecting devices to protect against short-circuit current for a range of installation conditions. T9 Selecting devices for isolation and switching encompassing: requirements for the provision of the isolation of every circuit in an electrical installation. need for protection against mechanical movement of electrically activated equipment. AS/NZS 3000 requirements for selecting devices for isolation and switching for a range of installations and conditions. T10 Switchboards encompassing: AS/NZS 3000 and local supply authority requirements for switchboards. tariff structures for the supply of electricity. equipment installed at the main switchboards with capacities up to 400 A per phase. layout of a main switchboard for an installation supplied with single phase single tariff whole current metering. layout of a main switchboard for an installation supplied with single phase multiple tariff whole current metering. layout of a main switchboard for an installation supplied with multiphase single tariff whole current metering. layout of a main switchboard for an installation supplied with multiphase multiple tariff whole current metering. layout of a main switchboard for a multiple tenancy installation with whole current metering. layout of a main switchboard, including metering, for an installation supplied with three phase CT metering. local supply authority requirements for connection of an electrical installation to the electrical supply system |