Evidence shall show that knowledge has been acquired of arranging electrical installations circuits, control and protection. All knowledge and skills detailed in this unit should be contextualised to current industry practices and technologies. KS01-EG063A Electrical installations — arrangement, control and protection Evidence shall show an understanding of circuit arrangements, control and protection of electrical installations that comply with the Wiring Rules and Service Rules to an extent indicated by the following aspects: T1 Safety principles to which electrical systems in building and premises shall comply. Safety principles are given in Part1 (Section 1) of the Wiring Rules AS/NZS 3000 with deemed-to-comply requirements given in Sections 2 to 8. Compliant methods for providing protection - include those for providing protection against direct and indirect contact; thermal effects; unwanted voltages; overcurrent; fault currents; overload; overvoltage; injury from mechanical movement. Requirements for installation design and selection of equipment - includes compliant protection arrangements; correct functioning; compatibility with supply; estimation of maximum demands; voltage drop considerations; arrangement of circuits and the like T2 Circuit and control arrangements encompassing: reason for dividing electrical installations into circuits 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 for a particular installation. diagrams/schedules of circuits for given installations. application and arrangements of SELV and PELV circuits application and arrangement of an isolated supply T3 Hazards and risks in an electrical installation encompassing: effects on the human body of various levels of a.c. and d.c. current and duration of current flow for various current paths. risk of ignition of flammable materials due the thermal effects of current or electric arcs in normal service of an electrical installation. risk of injury from mechanical movement of electrically actuated equipment. Protection against direct contact (basic protection) acceptable methods use of extra-low voltage T4 Protection against indirect contact encompassing: indirect contact with live parts of an electrical installation may occur. methods and devices that comply with the Wiring Rules for providing protection against indirect contact. components of the 'automatic disconnection of supply' method of protection against indirect contact. the terms ‘touch voltage’ and ‘touch current’. the current path when a short circuit fault to exposed conductive parts of an appliance occurs. protection against indirect contact is by the use of Class II equipment and by electrical separation. additional protection by use of Residual Current Devices (RCDs) protection against indirect contact by use of extra-low voltage and electrical separation. Protection requirements for damp situations. T5 Earthing encompassing: the terms: earthed, earthed situation, earth electrode, equipotential bonding, multiple earthed neutral (MEN) system, protective earth-neutral (PEN) conductor, main earthing conductor, protective earthing (PE) conductor, functional earthing, MEN link. selection of minimum size-earthing conductor for a range of active conductor sizes and materials. parts of an earthing system and the purpose of each. typical arrangement for a MEN earthing system. arrangements of protective earthing conductors that comply with the Wiring Rules. requirements for equipotential bonding in a range of installation situations. Installation of a MEN earthing system for a single phase installation T6 Protection against overload and short circuit current encompassing: overload current or fault currents in an electrical installation. equivalent circuit of an earth fault-loop level of fault current possible at a given point in an installation from the fault-loop impedance and data from the electricity distributor. methods and devices that comply with the Wiring Rules AS/NZS 3000 for providing protection against the damaging effects of overload and fault current requirements for co-ordination between protective devices and conductors requirements for co-ordination of protection devices for discrimination and back-up protection. T7 Devices for automatic disconnection of supply encompassing: operating principles of thermal/magnet circuit breakers. operating principles of common types of fuses. operating principles of residual current devices (RCD). time/current curves tripping characteristics of various types of circuit breakers that comply with the requirements of the Wiring Rules. time/current curves fusing characteristics of various types of fuses that comply with the requirements of the Wiring Rules. time/current curves tripping characteristics of various types of RCDs that comply with the requirements of the Wiring Rules. factors in a fault loop that will affect the impedance of the circuit. maximum impedance of an earth fault-loop to ensure operating of a protection device. selecting a fuse for fault current limiting protection. drawing switchboard wiring arrangements of 2-pole RCDs, 4-pole RCDs, combination RCD/MCBs. T8 Protection against over voltage and under voltage encompassing: causes of over voltage and how this may affect the electrical system. methods for protection against over voltage. causes of under voltage and how this may affect the electrical system. methods for protection against under voltage. T9 Control of an electrical installation and circuits encompassing: switch types, current and voltage ratings and IP rating and where these apply. switching requirements for isolation, emergency, mechanical maintenance and functional control. control arrangement for complete installations with and without safety services and an alternative supply. T10 Switchboards / distribution boards encompassing: Purpose, types and applications. Physical and circuit arrangements for whole current and CT metering. Physical and circuit arrangements of main switches, circuit protection devices, fault-current limiters and metering equipment and other distributor equipment. compliance requirements (includes location and access, arc fault protection, identification, construction suitability, equipment marking, wiring, fire protection and arc-fault protection). |