Evidence shall show that knowledge has been acquired of safe working practices and solving problems in electromagnetic devices and related circuits. The knowledge and skills shall be contextualised to current industry standards, technologies and practices. KS01-EG101A Electromagnetic devices and circuits Evidence shall show an understanding of electromagnetic devices and circuits to an extent indicated by the following aspects: T1 Magnetism encompassing: magnetic field pattern of bar and horse-shoe magnets. magnets attraction and repulsion when brought in contact with each other. common magnetic and non-magnetic materials and groupings (diamagnetic, paramagnetic and ferromagnetic materials). principle of magnetic screening (shielding) and its applications. practical applications of magnets construction, operation and applications of reed switches. T2 Electromagnetism encompassing: conventions representing direction of current flow in a conductor. magnetic field pattern around a single conductor and two adjacent conductors carrying current. Using the “right hand rule” to determine the direction of magnetic field around a current carrying conductor. direction of force between adjacent current carrying conductors. effect of current, length and distance apart on the force between conductors (including forces on bus bars during fault conditions). magnetic field around an electromagnet. Using the “right hand rule” to determine the direction of magnetic field around a current carrying coil. magnetomotive force (m.m.f.) and its relationship to the number of turns in a coil and the current flowing in the coil. practical applications of electromagnets. T3 Magnetic circuits encompassing: magnetic characteristic curve for various materials and identify the various regions. Identify the various conditions of a magnetic material from its Hysteresis loop. factors which determine losses in magnetic material. methods used to reduce electrical losses in a magnetic circuit. magnetic flux (definition, unit and symbol). reluctance as the opposition to the establishment of magnetic flux. permeability (definition, symbol and unit). difference for magnetic and non-magnetic materials in regards to reluctance and permeability. calculation of m.m.f., flux or reluctance given any two values. flux density (definition, symbol, unit and calculation). magnetising force (definition, symbol, unit and calculation). common magnetic circuit types. effect of an air gap in a magnetic circuit. terms “magnetic leakage” and “magnetic fringing”. T4 Electromagnetic induction encompassing: principle of electromagnetic induction (Faraday’s law of electromagnetic induction). applying “Fleming’s right hand rule” to a current a carrying conductor under the influence of a magnetic field. calculation of induced e.m.f. in a conductor given the conductor length, flux density and velocity of the conductor. calculation of induced e.m.f. in a coil given the number of turns in a coil and the rate of change of flux. calculation of force on a conductor given the flux density of the magnetic field, length of the conductor and the current being carried by the conductor. Lenz’s law applications of electromagnetic induction T5 Inductance encompassing: construction of an inductor, including a bifilar winding inductor. Australian Standard circuit diagram symbol for the four types of inductor. effect of physical parameters on the inductance of an inductor. common types of inductor cores. applications of the different types of inductors. definition of terms self induction, inductance and mutual inductance. calculation of value of self induced e.m.f. in a coil. mutual induction occurs between two coils. graphical relationship between load voltage, current and self induced e.m.f. in a single d.c. circuit having inductance. practical applications for the effects of self and mutual induction. undesirable effects of self and mutual induction. definition of term “time constant” and draw the characteristic curve as applied to a series circuit containing an inductor and a resistor. (LR circuit)Calculation of value of the time constant for an LR circuit given the values of the components. time constants required for the current in an LR circuit to reach its final value. determining of instantaneous values of voltage and current in an LR circuit using a universal time constant chart. T6 Measurement Instruments encompassing: moving coil, moving iron, dynamometer meter movements and clamp testers. practical applications for moving coil, moving iron and dynamometer meter movements. Calculation of resistance of shunts and multipliers to extend the range of ammeters and voltmeters. factors to be considered in selecting meters for a particular application. safety category of meters and their associated applications. steps and procedures for the safe use, care and storage of electrical instruments. T7 Magnetic devices encompassing: construction, operation and applications of relays. construction, operation and applications of contactors. magnetic methods used to extinguish the arc between opening contacts. construction, operation and applications of Hall Effect devices. operation and applications of magnetostriction equipment. construction, operation and application of magnetic sensing devices. T8 Machine principles encompassing: basic operating principle of a generator. applying Fleming’s right hand rule for generators. basic operating principle of a motor. applying Fleming’s left hand rule for motors. calculation of force and torque developed by a motor. T9 Rotating machine construction, testing and maintenance encompassing: components of a d.c. machine. difference between a generator and a motor in terms of energy conversion. nameplate of a machine. using electrical equipment to make electrical measurements and comparison of readings with nameplate ratings. Identification of faults in a machine from electrical measurements. care and maintenance processes for rotating machines safety risks associated with using rotating machinery. T10 Generators encompassing: basic operation of a d.c generator. calculation of generated and terminal voltage of a d.c. shunt generator prime movers, energy sources and energy flow used to generate electricity. types of d.c. generators and their applications. methods of excitation used for d.c generators. equivalent circuit for a d.c. generator. importance of residual magnetism for a self excited generator. open circuit characteristics of d.c. generators. load characteristics of a d.c generator. reversing the polarity of a d.c. generator Connect and test a d.c generator on no-load and load Identify safety risks associated with using generators. T11 Motors encompassing: operation of a motor and its energy flow. effect of back e.m.f. in d.c. motors torque as the product of the force on the conductors and the radius of the armature/rotor. types of d.c. motors and their applications. circuit diagrams for the types of d.c. motors. equivalent circuit for the types of d.c. motors. calculation of power output of a motor. characteristics of the different types of d.c. motors. connection and testing a d.c. shunt motor on no-load and load reversing the direction of rotation of a d.c. motor. safety risks associated with using motors (include risks of series d.c. motors). T12 Machine efficiency encompassing: losses that occur in a d.c machine. methods used to determine the losses in a d.c. machine. calculation of losses and efficiency of a d.c machine. efficiency characteristic of a d.c. machine and the conditions for maximum efficiency. application of Minimum Energy Performance standards (MEPS). methods used to maintain high efficiency. |