Excavator damages underground residential service cable causing service panel fire
July 25, 2019
An excavator operator was digging a new trench outside the building. The excavator hooked the cable and pulled it which also pulled it out of the service panel.
The cable connector lugs on the main circuit breaker in the panel, were now broken and pulled out of the panel. Contact between the energized damaged lugs and the grounded panel would create an arc and start a fire. The fire damaged the panel and the wall of the building.
Evidence was removed at the time of investigation, including but not limited to, the service cable and the service panel.
The reporting electrical contractor provided photos of the damaged equipment and stated that the excavator contacted the underground cable and pulled it out of the connected service panel.
The photos show the excavated trench, a section of the damaged cable and a burnt service panel with the remains of the circuit breaker connector lugs hanging below the panel.
It is possible to state that the service cable may not have been buried or marked correctly or the excavator operator may not have identified the underground cable installation.
The service cable was contacted by the excavator and pulled from the service panel which likely dislodged cable, and broken lugs from the circuit breaker, resulted in the arcing which resulted in the fire.