Safety Alert!! 480 Volt Breaker Flash

From the Limerick Generating Station

Safety Alert 2R07-06:

During the installation of a 480 Volt breaker in support of maintenance, a large flash was experienced. The origination site of the flash was the breaker above the breaker being installed.

The line cables of the breaker that was above the breaker being installed rested on a bracket shared by both the upper and lower breakers. The vibration induced by the breaker installation allowed the degraded insulation of the line side wires of the above breaker to fault to the bracket causing the flash.

The picture to the left shows the faulted line side cable of the breaker above the breaker being installed.

The proper use of PPE likely prevented significant personnel injury.