10-14-04 -- Shock Protection Research Project Expands Scope
10-15-04 – The Electrical Contracting Foundation has expanded the scope of its mobile equipment grounding study to include other protective practices. The revised research project will now investigate the use of isolation and insulation, along with grounding, to protect workers on the ground effectively during construction and maintenance operations.Traditionally, safety equipment and procedures used in high-voltage utility construction have focused on protecting workers aloft, the linemen working on energized lines and equipment. But line construction also creates serious hazards for nearby personnel and equipment on the ground. The new scope of the Foundation’s ‘Worksite Shock Protection’ project is to:
Develop and recommended practices based on worksite conditions for protecting workers on the ground from primary shock during overhead line construction and maintenance operations through grounding, isolation, insulation, or a combination of these methods.
Hazards of Different Voltages and Systems
The research project task force held its second meeting on September 30 in Chicago. Ten representatives from line construction companies represented by NECA attended the session which was hosted by principal researcher Thomas E. Glavinich, P.E., D.E., of the University of Kansas.
Task force members agreed that shock protection techniques for distribution and transmission operations should be investigated separately because the different voltage classes create hazards of different magnitudes. Distribution is usually defined as including systems rated up to 69,000 volts while long-distance transmission can operate at up to 800,000 volts.
The task force also plans to investigate different power system configurations (delta, wye, corner-grounded, etc.), to evaluate what effect these have on the severity of line-to-ground faults.
Research in Phases
Due to the size and complexity of the Electrical Contacting Foundation’s research project, it is divided into three phases.
- Phase I is currently underway and will be completed this year; it involves establishing the need for better worker protection, investigating current industry practices, and developing a field-testing program.
- Phase II, which begins in 2005, will include practices for protecting workers under varying site and electrical system conditions.
- Phase III, in 2006, will develop data for a NECA National Electrical Installation Standard (NEIS) for protecting workers on the ground from shocks during overhead line construction and maintenance operations.