Abstract: An employee was starting a pulpwood log grinder using a General Electric Limitamp controller (Model No. IC7160). He engaged the on-off isolation switch. When he pushed the start button, the lower portion of the 4160-volt controller, which contained three fuses, failed. The employee was burned by the ensuing electric arc. He was hospitalized with burns to his neck, hand, arm, abdomen, and knee. An immediate investigation revealed that a power stab for the middle phase had broken off , and the controller was replaced. Three days later, another employee was performing the same operation. He was following different procedures that were instituted as a result of the accident. He was standing off to the side of the new controller, when it also failed. This time the ensuing electric arc ignited gases and an explosion resulted. The employee was hospitalized with burns to his forearm.