Department of Labor
Mine Safety and Health Administration

Accident Info-Gram
June 2003

Phase Rotation Meter Short-Circuits

On June 24, 2002, an electrical near-miss incident occurred at a surface mine in District 8. A contractor, who did not have a MSHA Surface Electrical Qualification, was at the mine electrical substation working under the direct supervision of a qualified electrician. The contractor was checking the substation to determine what was needed to relocate high voltage power lines in the substation. While inside an electrical enclosure within the substation, the contractor connected a phase rotation meter to a 4160-volt AC phase circuit. The phase rotation meter was not rated for 4160-volts and short-circuited. The contractor was wearing low voltage gloves and a face shield. He received no injuries from the incident.

• Do not trouble-shoot or test high-voltage circuits while they are energized. This is an unsafe work practice.
• Persons trained to perform electrical work and to maintain electric equipment may only do testing and trouble-shooting on low and medium voltage energized circuits as part of a training program.
• Ensure that test equipment is rated for the voltage to be tested.

This information was provided by concerned miners in an effort to eliminate accidents. Accident or "close call" information within District 8 may be shared by contacting the MSHA office at (812) 882-7617.