Contractor Safety Share

Sharing safety information

480 Volt Temporary Wiring Causes Near Miss

480 Volt Temporary Wiring Causes Near Miss


Contractors were cutting electrical conduits to prep a building for demolition.  As the employee began to cut a piece of conduit with a sawzall, he cut into an unmarked live conduit.  The conduit was housing temporary wiring used to power an existing lift station after power to the building was isolated.  As the employee cut into the temporary wiring, it caused the 480 volt temporary wiring to arc.  Upon seeing sparks, the employee immediately stopped cutting and notified his supervision.


All 13,200 volt lines powering the building had been separated several days prior to the incident at the load center by the owner.  A separate contract firm then cut visual separations in the high voltage lines at the exterior of the building and also in the substation located in the basement.  Temporary wiring powering the lift station was installed in December 2007, with the power being fed from a nearby electrical vault.  The temporary wiring was encased in conduit and installed on the north side of the building, where it entered the basement.  After entering the basement, the conduit was hung alongside previously existing conduit.  However, the newly installed conduit was not marked flagged or painted.


No injuries were reported as a result of this incident.


Factors to consider at your site and/or project include, but not limited to the following:

  1. Mark live conduits or energized equipment to indicate hazard.
  2. Utilize a checklist to help ensure all hazards are identified prior to demolition activities commencing.
  3. Ensure work activities follow the previously laid out Work Permits.
Consider this example as you complete today’s work activities.

Safety Flash Action Items:
  • Date Contractor Safety Flash posted for all employees to review: _______________
  • Safety Talk meeting date: _______________
  • Full employee attendance and participation at safety meeting to review this incident (documentation required).
  • Employees understand urgency in protecting themselves and others.
  • Supervisors and Employees are clear which items shared in this Safety Flash are mandatory.
  • Employees/Supervisors will focus on recommended actions during future work activities of a similar nature.
Contract Firm Management Rep Signature____________________

THINK about the hazards associated with your particular work, and the steps that can be taken to increase safety on your job.


If you have questions about this CONTRACTOR SAFETY FLASH, please contact



(This Safety Flash has been previously issued and is to be used for reference purposes only)


Comments are closed