Document ID: chunk:federal_register_of_legislation:F2016L00407:body:0:p51
Version: federal_register_of_legislation:F2016L00407
Segment Type: other
Provision Reference: 
Character Range: 144339–149267

the energy to cause an explosion and/or melt metallic switchboard cubicles and equipment. Arcs may cause severe burns to the skin and flash burns to the face and eyes. Inhaled hot gases and molten particles can cause serious internal burns to the throat and lungs. Injury can also occur through the impact from flying debris and dislodged components. Circuit protection devices may not operate in such circumstances.
Testing, fault finding or working on or near low voltage equipment      * Voltages between phases and between phases and neutral.
                                                                        * Voltages between phases and earth.
                                                                        * Voltages across open switch contacts, for example voltage across a light switch on an incandescent lighting circuit or the voltage across a bus tie where one side is de-energised.
                                                                        * Voltages on disconnected conductors (particularly neutrals).
                                                                        * Voltages from sources near the work being performed, for example:
                                                                              + working on a remote area power supply where both a.c. and d.c. voltages may be present
                                                                              + repairing lights on a shop fascia when overhead power lines are nearby
                                                                              + working on transducer circuits when other a.c. and d.c. circuits are present
                                                                              + working on a power system with multiple circuits that may be of multiple potentials.
                                                                        * Voltages on the circuit being worked on from other sources including:
                                                                              + illegal connections or reconnections
                                                                              + Uninterruptible Power Supplies (UPS) and backup supplies
                                                                              + motor generators or alternators
                                                                              + d.c. on a.c. circuits or a.c. on d.c. circuits
                                                                              + harmonics, for example 3rd harmonic 150 Hz in neutrals and earths where there is a large fluorescent light load and switch mode power supplies
                                                                              + back Electro Magnetic Forces (EMF) from collapsing magnetic fields or rotating machinery
                                                                              + solar panels or photovoltaic.
                                                                        * Voltages across undischarged capacitors.
                                                                        * Voltages across the secondary terminals of transformers, including current transformers.
                                                                        * Voltages caused by static electricity, leakage or discharge, or lightning.
                                                                        * Voltages between energised exposed conductors and the surrounding environment (including metalwork, damp situations, other conductive surfaces and persons nearby).
                                                                        * Voltages between parts, or open-circuited parts of one earth system,
                                                                          or voltages between different earthing systems.
                                                                        * Induced voltages from sources other than the circuit being worked on,
                                                                          for example nearby circuits or radio frequency transmitters.
                                                                        * Multiple supply sources (more than one source of supply or energised circuit may be available on the premises), for example 'essential services' on a switchboard, emergency backup generators or UPS.
                                                                        * Electrical testing or operating equipment with open enclosures in hazardous areas (as defined by AS/NZS 3000:2007).
                                                                        * The potential (voltage) between parts of the earth in Multiple Earthed Neutral (MEN) systems can change, sometimes causing electric shocks. The changing earth potential can be due to a number of causes including a high