An apprentice electrician at an underground metals mine in New South Wales recently experienced an electric shock while performing on-site maintenance.
The apprentice was accompanied by an experienced electrician at the time, with the pair performing a range of electrical maintenance tasks, including tightening the terminals on a magnet starter with two panels side-by-side.
The apprentice was in one panel and the electrician in the other, tightening terminals.
According to reports, the apprentice touched the live side of the main isolator with a 1000-volt insulated screwdriver.
The screwdriver was insulated with interchangeable heads, and the fingers on the right hand were used to access the terminal section, which was also insulated.
The voltage was 415V 3 phase and the apprentice came in contact with a phase to earth voltage (240 volt).
The isolations applied to the panel were incorrect (personal locks and tags applied to outgoing isolators, not the main isolator of the board).
In its investigation of the incident, the NSW Resources Regulator said the task of terminal tightening within the panel should have called for an upstream isolation.
“Mine operators need to ensure safe systems of work are developed for people dealing with electrical plant and electrical installations that include the isolation, dissipation and control of all energy sources from electrical plant or electrical installations,” the Regulator said.
“The failure to isolate sources of electrical energy before undertaking electrical work exposes workers to a high level of risk from electrocution, electric shock, burns and/or injuries resulting from ignition of flammable gas or dust, unintended operation or movement of plant.”
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