Switchboard safety — understand the risks

Queensland’s Electrical Safety Office is reminding electrical workers to carry out a risk assessment before removing switchboard panels. If workers identify any hazards, they must put control measures in place to address the risk of electric shock, explosion or fire.

Electrical workers have been injured when they have removed switchboard escutcheon panels from an energised switchboard. As they have removed panels, electrical cables in the switchboard have become dislodged, resulting in an arc flash and causing severe burns.

Electrical safety laws prohibit work on energised electrical equipment unless:

• it is necessary in the interests of health and safety that the electrical work is carried out while the equipment is energised (for example, it may be necessary for lifesaving equipment to remain energised and operating while electrical work is carried out on the equipment)
• it is necessary that the electrical equipment to be worked on is energised in order for the work to be carried out properly
• it is necessary for the purposes of testing to ensure the equipment is de-energised
• there is no reasonable alternative means of carrying out the work.

Electrical workers must never work on energised electrical equipment just because it is more convenient. The Electrical Safety Office is reminding workers to consider their environment and the nature of work they are performing. If working with a high fault level, workers must consider putting the highest measures of controls in place — which would be to eliminate the hazard altogether and de-energise the switchboard.

If workers were working on a switchboard supplied by a 500 kVA transformer, the fault level would be near 14,000 A, which could result in an arc flash with temperatures of 19,400°C. In this circumstance the risks of working near the live parts can be just as dangerous as the live work itself, and you should de-energise the switchboard before starting work.