Voltage tests were being performed in a bucket of the MCC with a multi-meter that had the test lead connected to the amperage port and an underrated fuse. When connected to the 600-volt source, the multi-meter shorted, leading to an arc flash. The arc flash caused burns to the face and hands and pushed the worker back, landing on their knees.
The MCC has arc flash and shock hazard warning labels that provide direction for personal protective equipment (PPE) requirements, working distance, limited and
restricted approach. The PPE requirements for arc flash protection gear for the MCC indicate the use of category 1, meaning 4 cal/cm2 gear.
Arc flash gear ranges from category 1 to 5, with category 5 being the highest rating.
- Allen-Bradley 1200-amp (horizontal) 300-amp (vertical) Bus ratings.
- 600 VAC maximum – 3 phase Motor Control Center.
- Motor control center bucket.
- MCC Arc Flash Protection-Shock Protection Warning Label states direction for PPE requirements, working distance, limited and restricted approach.
- MCC bucket voltage detector lamps were lit, and voltage was present at time of incident.
- Multi-meter Fluke 117- Data sheet- Fuse for A input- 11 A, 1000V FAST Fuse (Fluke PN 803293)