A worker received an electric shock and suffered burnt fingers when he came in contact with exposed live busbars in a sub-board (distribution board or switchboard).

The sub-board did not have enough pole fillers to cover all live points on the board. The power was not isolated and the door to the live sub-board was left open. A worker in the vicinity, in answering a mobile phone call, lost concentration and inadvertently leant against the live sub-board, sustaining an electric shock injury.

Electrical sub-board installation is common during construction. Electrical work must be performed by qualified and registered people. Appropriate guarding must be in place to prevent other people from making contact with or accessing live parts in sub-boards.

Probable causes

This incident may be attributed to:

  • the sub-board having exposed live parts due to insufficient pole fillers
  • the door of the live sub-board being left open when unattended
  • distraction (from the mobile phone call) while working near the exposed live parts increasing the risk of electric shock injury through inadvertent contact.
An electrical ‘sub-board’ with insufficient pole fillers
An electrical ‘sub-board’ with insufficient pole fillers
Exposed live busbars in an electrical ‘sub-board’
Exposed live busbars in an electrical ‘sub-board’

Action required

You must:

  • fully protect all live parts in sub-boards with pole fillers
  • close the door of the live sub-board and main distribution board prior to turning on the power unless testing is being performed
  • move a safe distance away from potential hazards when performing unrelated tasks (like answering a mobile phone call), thereby minimising the risk of inadvertent exposure.