UEEEL0014 - Isolate, test and troubleshoot low voltage electrical circuits
Overview
This unit involves the skills and knowledge required to isolate, test and troubleshoot electrical circuits operating at voltages up to 1,000 volts (V) alternating current (a.c.) or 1,500 V direct current (d.c.).
It includes working safely, isolating electrical circuits, evaluating low voltage (LV) electrical circuits, applying systematic fault-finding procedures, conducting repairs and completing the necessary documentation.
The skills and knowledge described in this unit require a licence or permit to practice in the workplace where work is carried out on electrical circuits and equipment which are designed to operate at voltages greater than 50 V a.c. or 120 V d.c.
Assessment
For Melbourne campuses
Assessment tasks will be designed to reinforce & extend knowledge and skill competence within set & controlled parameters in accordance with each unit’s learning outcomes & performance criteria requirements, incl the setting of work based practical application tasks designed to provide evidence of competence outcomes, within periodic and scheduled timelines.
Students will be expected to demonstrate the following required skills:
*applying work health and safety (WHS)/occupational health and safety (OHS) workplace procedures, including:
*identifying and assessing hazards and risks, and implementing control measures
*selecting and using correct tools and equipment to isolate, test and troubleshoot electrical circuits
*performing safe isolation of equipment, including:
*preparing a safe work method statement (SWMS) or job safety analysis (JSA) for effective and safe isolation
*applying safe methods to identify sources of supply to be isolated
*identifying appropriate points of isolation
*isolating equipment from all sources of supply by safely switching off switches or circuit breakers, removing fuses or links, or removing circuit connections
*securely isolating devices by applying an isolation securing device which requires a deliberate action to engage or disengage
*applying a personal danger tag, lock-out or permit system
*applying safe methods to confirm effective and safe isolation from all sources of supply
*identifying the limits of the safe work area, discharging any stored energy
*proving de-energisation of all relevant electrical equipment and conductors, including:
*testing the voltage tester on a known live source, between all conductors and a known earth, between conductors
*retesting the voltage tester on a known live source for correct operation
*correctly using personal protective equipment (PPE) whilst performing effective isolation and operation of low voltage (LV) equipment
*completing visual inspection of the electrical installation for compliance with regulatory requirements including:
*protection requirements
*general condition
*mains/sub-mains
*switchboards
*wiring systems
*equipment and accessories
*earthing
*conducting mandatory testing to ensure:
*compliance with AS/NZS 3000 mandatory test requirements and the application of mandatory tests following guidance of AS/NZS 3017
*insulation resistance of mains, sub-mains and final sub-circuits meets the regulatory requirements
*earth continuity of the main earthing conductor, protective earthing conductors, combined protective earthing and neutral (PEN) conductors and bonding conductors meet the regulatory requirements
*polarity of active, neutral and earth conductors including phase sequence and rotation meet the regulatory requirements
*correct connections of active, neutral and protective earthing conductors are tested to ensure no short circuits between conductors, no transposition of conductors that could result in the earthing system or exposed conductive parts becoming energised, and no interconnection of conductors between different circuits, in accordance with regulatory requirements
*verification that earth fault-loop impedance limitations are not exceeded in accordance with regulatory requirements
*residual current devices (RCDs) have been correctly installed, their function verified, and the isolation of all switched poles verified, in accordance with regulatory requirements
*testing and verifying alternate supplies, including:
*completing continuity and voltage testing, including output voltage of device/s
*earth resistance testing, including:
*continuity of main earthing conductor
*checking earth bonding integrity and equipotential bonded parts
*insulation resistance test
*polarity and checking operation of control device/s
*verifying records for the date of initial certification are completed in accordance with regulatory requirements
*locating and diagnosing common faults in electrical circuits
*testing and diagnosing high impedance or open circuit neutral fault
*repairing and/or replacing parts to rectify faults in accordance with AS/NZS 3000
*applying steps required to ensure the fault does not re-occur
*completing final testing and re-commissioning
*completing work and documenting activities.
Required reading
The qualified trainer and assessor will advise students of class notes, reading materials produced by VU Polytechnic and further support via VU Polytechnic e-learning system and/or in person.
As part of a course
This unit is studied as part of the following course(s):