Are you safe with your temporary protective grounds? (Case study)

This case study is based on an arc flash incident that occurred at a pellet plant facility located in Port-Cartier, Québec, Canada. The incident occurred while replacing a 2000A 600V MCC main molded breaker by a more recent model, as recommended by our technical service. One of the causes of this arc flash incident was the temporary protective ground that didn´t withstand the short circuit current when the power accidentally got back to the workspace. The worker suffered 1^st degree burns to his face and hand. A full investigation was done. The investigation revealed a couple of facts, but the one we´ll focus on in this case study is that the temporary protective GND wasn´t big enough to withstand the short circuit current available at that point. All the proper procedures had been followed. That incident lead to a modification in our procedures and was communicated to other electrical workers.