Fires around high-voltage transmission lines require special precautions. Fire, smoke and even heat can act as conductors and cause electrical arcs from transmission lines to the ground. Avoid the dangers of step potential by maintaining appropriate safety clearances:
- If the flames are 100 feet or farther from energized transmission lines, keep all personnel and equipment at least 30 feet away.
- If there are flames within 100 feet of the lines, stay at least 300 feet away.
If you are instructed to protect exposures near a transmission line using water, use a 30-degree fog pattern with at least 100 psi of pressure. Never use a solid stream.