JICOSH was closed in 2008. For further information, please contact JISHA.
JICOSH Home > Case Studies > Case No.112
Case No.112

A worker is killed by electric shock while replacing the ballast in a fluorescent light panel




Click Here
[Description of the Accident]

This accident took place during work to replace the ballast in a fluorescent light panel in the first basement of the building.

The procedures to carry out the ballast replacement work entailed climbing above the ceiling panels, removing the failed ballast, and connecting the wires between the new ballast and the lighting fixture.

The victim, who had been dispatched as the site supervisor by the subcontractor requested to make the repairs, climbed above the ceiling panels, put such tools as a set of needle-nosed pliers, a Phillips screwdriver, etc., on the sheet metal exhaust air duct, and started work to replace the ballast.

A short time later, the site supervisor who had been dispatched to the site by the contractor heard a loud bang as he was standing under the lighting fixture. When he climbed above the ceiling panels to see what had happened, he saw the victim lying on his back with his buttocks on the exhaust duct.

On the basis of an investigation carried out later, it was presumed that the burn marks on the fingertips of his left hand indicated that the victim had touched his left hand to a charged section carrying 240 volts while carrying out hot-line operations. This created a circuit through the sheet metal exhaust duct on which the victim was sitting and caused his death due to electric shock.


[Causes supposed]

1. The work to replace the ballast, which was installed in the lighting fixture, was being carried out without shutting off the power switch for the lighting.

2. The victim was carrying out hot-line operations with his bare hands, without wearing any protective equipment that included an insulation performance corresponding to the given voltage.

3. As the victim was perspiring profusely because the temperature above the ceiling was over 30 degrees Celsius, contact resistance with the sheet metal duct on which he was sitting had declined substantially.

4. No operational safety procedures had been prepared.


[Type of business] -
[Caused by] Power facility
[Type of accident] Electric shock
[Number of victims] One fatality


toptop