This describes the essential skills and knowledge and their level required for this unit Evidence shall show that knowledge has been acquired of safe working practices and disconnecting and reconnecting fixed wired control devices connected to a Low Voltage supply All knowledge and skills detailed in this unit should be contextualised to current industry practices and technologies KSEPA Electrical Safety Principles Evidence shall show an understanding of electrical safety principles to an extent indicated by the following aspects T The basic electrical circuit encompassing elements of a simple electric circuit (supply, control switch, protection device and load). definition the symbol and the abbreviation of the unit for electromotive force potential difference current resistance types of electrical load need for devices to afford electrical protection and the mechanisms used in protection devices including resetting symbols for the components of a basic electrical circuitconnection of the circuit from the schematic diagram ac supply both single and three phase and dc supply correct connection and use of voltmeters and ammeters including the selection of correct range in terms of magnitude and whether the supply is ac or dc need for isolating testing and tagging electrical circuits isolation testing and tagging accessories in a simulated environment connecting a simple electrical circuit including supply control switch and load measuring voltage and current within a simple circuit T Relationships in an electrical circuit encompassing relationship between Voltage Current and Resistance connection of meters to determine resistance from voltmeter and ammeter readings using a variation of the Ohms Law relationship predicting changes in circuit parameters for altered values of voltage current and resistance definition of power in electrical terms for dc or resistive ac circuits using circuit readings determine power using the appropriate equations symbols and unit abbreviations including the use of multiples and sub multiples T Electrical diagrams encompassing symbols used for fuse circuit breaker isolator normally open contacts normally closed contacts coil energy meter ac motor transformer using a block diagram as means of developing concepts and understanding producing a block diagram of a simple circuit function of single line diagrams including their application in three phase systems definition of a circuit or schematic diagrams wiring diagrams connecting a simple circuit using a schematic diagram noting the wide degree of variety in the way the conductors may be run producing the wiring diagram of the connections used in following the schematic diagram connecting a simple circuit following a wiring diagram producing a schematic diagram from the wiring diagram T Test equipment selection and care encompassing fault currents and the implications of incorrectly connecting a meter to a high fault current source category ratings of multimeters in terms of their breaking capacity fault current interruption and identification of the appropriate category of instrument for typical domestic work and for typical commercial work regulatory requirements in regard to the maintenance and testing of test instrumentation steps and procedures for the safe use care and storage of electrical instruments selecting test equipment for given situations T Test equipment Voltage measurement encompassing voltage measurement meters connected in parallel operation of series test lamps construction of a set of series test lamps with emphasis on safety requirements using a set of series test lamps operation of neon test pencils and test screwdrivers with emphasis on the limitations of their safe use operation and limitations of voltage probes including their limitations using an analog multimeter for voltage measurement ensuring the following setting zero correct scale ac or dc polarity and magnitude avoiding parallax error and estimating between division readings using a digital multimeter for voltage measurement ensuring the following correct range and no active conductors are connected to any meter earth T Test equipment Resistance measurement encompassing voltmeterammeter method of resistance measurement measuring resistance in a simple circuit using the voltmeterammeter method with emphasis on the correct choice of long or short shunt measuring resistance in a simple circuit using an analog multimeter ensuring the following setting zero selecting correct range estimating of between division readings measureing resistance using a digital multimeter insulation resistance and list the required minimum values for insulation resistance for low voltage wiring and low voltage equipment insulation resistance between active and earth the value for appliances incorporating heating elements insulation resistance needs to be measured at higher than supply voltage and list the voltages to be used conducting insulation resistance tests using a hand held tester after checking for zero and meter calibration continuity and what a continuity tester does checking the polarity of a three core extension cord using a continuity tester T Test equipment Current measurement encompassing advantages of the clipon method of current measurement measuring current in a simple circuit using a multimeter on the correct current range and explain why a series connection must be used measuring current using a clipon tong tester taking each circuit conductor in turn KSEPA Disconnect and Reconnect Control Devices Evidence shall show an understanding of disconnect and reconnect control devices to an extent indicated by the following aspects T Cable connections encompassing construction of typical power cables principle of operation of the following types of terminals stud screw tunnel faston and soldered cable preparation and terminating methods appropriate to each type of terminal including any special requirements which apply terminating cables using all of the above terminal types employing the correct preparation and the relevant terminating tools including the correct size soldering equipment T Protection for Safety encompassing dangers associated with earthfaults protection of persons against electric shock from earthfaults maintaining a low earthfault current path resistance components in an earthfault current path testing the resistance of a faultcurrent path regulatory issuesrequirementslimitations in regards to working live T Safety testing preparation and procedures encompassing faulty earthfault current paths using safe working practices when carrying out fault finding work Identification of earthing system components unsatisfactory resistance of a faultcurrent path actions to rectify unsatisfactory resistance of an earthfault current path or insulation T Isolating supplies encompassing regulatory requirements in regards to working deenergised and ensuring and maintaining isolation reasons for advising all personnel likely to be affected preventing others wanting to remake supply reason for isolation and approximate time of outage to allow planning of alternate activities identification the type and arrangement of circuits supplying equipment that is to be disconnected availability of supply is tested at an control devices about to be disconnected locating isolation devices eg lockable adjacent isolating switch or fusecircuit breaker at a distribution board usually identified at the control device determining the method of isolation to be used which available device isolating a supply at a fuse the fuse wedge is removed only after the control device is turned off and why the empty wedge is replaced once the fusible link has been removed tests to determine if an control device is turned off when isolating at a fusecircuit breaker use of and reason for danger tags at the point of isolation reason for the following steps testing on a known live supply testing for isolation retesting on a known live supply after confirming isolation T Disconnecting an control device ELV encompassing identification of the type and arrangement of circuits supplying equipment that is to be disconnected from a ELV single phase andor multiphase supply of voltages up to V ac or V dc procedures that ensure the safe isolation of the supply to control device which is to be disconnected disconnecting isolated electrical control device from fixed wiring with minimal damage to wiring system after ensuring no visible faults or damage and the recording of conductor connection sequence termination practices in regard to disconnected wiring T Reconnecting an control device ELV encompassing importance of checking the new electrical control device nameplate details against those of the control device being replaced need for high insulation resistance and the need to test insulation of volt control device at volts and identify the minimum acceptable value of insulation resistance between active testing procedures testing on a known live supply testing for isolation and retesting on a known live supply after confirming isolation need to disconnect circuit cables before undertaking insulation resistance testing compliance testing the control device insulation resistance test and continuity test need to ensure the following steps are taken when terminating cables stranded conductors are twisted tightly together appropriate lugs are used rather than simple loops under a nut eg soldered lugs or Ross Courtney Stanco or other solderless variety shake proof washers are used cables are not left under physical stress cables are protected when passing through metal openings conductors are doubled in tunnel connectors T Disconnecting an control devices LV encompassing identification of the type and arrangement of circuits supplying equipment that is to be disconnected from a single phase andor multiphase supply of voltages up to V ac or V dc procedures that ensure the safe isolation of the supply to equipment which is to be disconnected disconnection of isolated equipment from fixed wiring with minimal damage to wiring system after ensuring no visible faults or damage and the recording of conductor connection sequence termination practices in regard to disconnected wiring T Reconnecting an control device LV encompassing importance of checking the new control device nameplate details against those of the electrical control devices being replaced need to visually inspect and test the control device electrical characteristics using suitable test equipment to ensure equipment is safe to connect in regard to sufficiently high insulation resistance arrangements for protection against indirect contact are undamaged and in place appropriate IP rating and arrangements for protection against dangers of mechanical movement are undamaged and in place compliance testing of the fixed control device ie insulation resistance and continuity testing the disconnected control devices for faults open circuits partial open circuits short circuits partial short circuits and earth faults and recognise any unsatisfactory test results obtained procedures for equipment with unsatisfactory results unsuitability for reconnection identification of the type and arrangement of circuits supplying equipment that is to be reconnected to a single phase andor multiphase supply of voltages up to V ac or V dc procedures ensuring isolation of supply process to establish the integrity of the circuit to which the disconnected equipment is to be connected including testing the resistance between the protective earthing conductor and neutral conductor as applicable is sufficiently low ie not greater than ohms insulation resistance of the active conductors is greater than megohm engaging appropriately qualified person to rectify any noncompliance appropriate cable termination practices reconnection of control device to fixed wiring with minimal damage to wiring system continuity between exposed conductive parts of the equipment and the main earth or metal switchboard enclosure restoring supply after ensuring correct connections and all safety requirements have been met testing the supply at control device restoring all mechanical protection eg terminal covers checking operation of reconnected equipment T Produce documentation and reports encompassing need to produce status reports and documents to locate and identify isolation mechanisms for a wide range of circuits and associated loads production of reports and documents to use a suitable procedure to safely disconnect a component from a single phase supply andor multiphase supply content required in reports and documents used to safely determine the suitability of a component for reconnection to supply producing reports and documents for the safe reconnectioncommissioning of a component to the supply T Enterprise reporting and recording system encompassing purpose and extent of maintaining work activities records in an enterprise types of records for maintaining work activities in an enterprise methods for recording and maintaining work records work records for regulation requirements producing enterprise records and documents for the safe reconnectioncommissioning of a component to the supply |