WA’s Department of Mines, Industry Regulation and Safety recently issued a significant incident report over an incident in which an electrician was injured by a 1000V electric shock.
The electrician was fault-finding on his own in a vent fan control panel during night shift, and he was wearing 1000V Class 0 rubber gloves and attempted to remove a plastic cover to access control relays.
The cover fell to the floor of the panel and adjacent to a control transformer (1000V/110V) and he reached down to retrieve the cover and his glove caught on the sharp edges of exposed terminal lugs of the control transformer which punctured the rubber glove.
He received a 1000V electric shock through his wrist when the current arced between two exposed cable terminals through the puncture holes in the gloves.
He was able to remove himself from the panel and drove to the workshop, and another worker drove him to a regional hospital.
He was transported to Perth and has undergone multiple surgeries.
The report said there were a number of contributing factors:
The electrician was working near energised electrical equipment.
The electrician did not isolate or test before working on the equipment.
There was no protective shroud over the 1000V control transformer terminals.
The rubber insulating glove was punctured when pushed past sharp edges of the terminals.
Inadequate personal protective equipment (PPE) was being used.
The report subsequently recommended mining operations:
Design, install and maintain electrical installations and equipment in accordance with Australian Standard AS/NZS 3000 Electrical installations and other relevant standards
Ensure all workers are aware of and comply with emergency procedures
Ensure personnel qualified in first aid and a vehicle equipped to transport injured or sick workers are available at the mine site at all times when workers are onsite
Determine whether there is a requirement to work or fault find on or near the installation or equipment while energised. If workers are required to work on or near energised electrical equipment, duty holders are to:
undertake a written risk assessment performed by a competent person
prepare a written safe work method statement
select and use suitable safety equipment and PPE
Ensure a competent safety observer is present when work is carried out on or near an energised electrical installation unless the risk assessment has determined no observer is required for the proposed work.