Arc Flash Incident

Cause & Consequence

• Electricity, electrical discharge, short circuit or overload

Incident Location

Any Location Type

Incident Activity

Maintenance

Incident Info Source

Step change in safety

Specific Incident Equipment

A 480v main breaker on a motor control centre (MCC)

Lessons Identified

The contactor’s safety management process did not identify the training standards and procedures required for contractors to perform critical work. • The contractor’s standards did not address the hazards of working on exposed 480 volt terminals, barriers and breaker configuration for phase checking. • The process of training electrical workers to become “qualified” and understand the hazards associated with arc flash were not well defined nor applied consistently with new workers. • The ‘sheppards’ hook style phase stick was designed for overhead lines and was not the appropriate equipment/tool for checking this equipment. • Hazard identification and controls were not implemented even though the work involved energized electrical parts. • A Field-Level Hazard Assessment (FLHA) was not conducted prior to completing the phase checks to identify the hazards of performing this job.

Incident Recommendations

Review and enhance contractor selection process to ensure that training standards and procedures have been established for electrical contractors performing

• Develop an Arc Flash Hazard Study standard consistent with industry standards. Ensure that all analysis are conducted in accordance with this standard and that the results are communicated to personnel performing maintenance work.

• Revise/enhance Company standards and training program to address arc flash and electrical shock hazards.

• Work on high-voltage electrical equipment is a critical task and requires that a Field-Level Hazard Assessment (FLHA) be completed before beginning work. Additional Information: In addition to the Canadian Electrical Code (CSA C22.1-09), other relevant references include:

• NFPA 70E-2000 Standard for Electrical Safety Requirements for Employee Workplaces.

• IEEE Standard 1584-2002 Guide for Performing Arc Flash Hazard Calculations