By Tom Markel
Q: How close is too close to power lines when installing a tent?
A:Electrical hazards cause more than 300 deaths and 4,000 injuries in the workplace each year, which means electrical accidents rank sixth among all causes of work-related deaths in the United States, according to the Electrical Safety Foundation International (ESFI).
High-voltage utility lines start at 4,160 volts and increase from there. Electricity can arc from a wire, without direct contact, to something close enough to provide a path to the ground. A common misconception is that power lines require insulation—they don’t. Insulation is only required to maintain the integrity of the system or if people will contact wires in the normal course of events. The codes regulating the height of a line allow a high voltage line to be, at the lowest point, 12 feet from the ground, 15 feet if above a driveway and 18 feet if above a roadway. A tent frame, frame jack, quarter or center pole for most tents could easily contact lines at those heights.
OSHA requires all contractors, unless specifically equipped and trained, to maintain 10 feet from power lines, including from a pole to a building. The “danger zone” 10-foot-rule applies during installation and removal, not just during the event. Don’t push lines around with the tent top. That thin layer of vinyl is no match for high voltages. And watch tent jacks, frames and clearspan arches for clearance.
A clearance factor of 1.5 for pole tents and 1.25 for frame and clearspan tents times the peak height should maintain the minimum distance needed when locating the peak of the tent near any overhead utilities. For example, if the center pole is 20 feet high, the peak’s location should be 30 feet away from the nearest overhead utility (1.5 x 20 feet=30 feet). The top of the frame jack still needs 10 feet of clearance from a line, even when using this rule.
Finally, if the worst happens and equipment comes in contact with high voltage, call 911 and then the utility company. Wait for them to arrive before attempting removal. If someone is trapped, even if they’re not being shocked, keep your distance and instruct him or her to remain still—a change of position could be fatal.
Electricity is essentially lazy; it wants to find the easiest path to ground. Don’t be lazy and give it that path—look up, keep your distance and be careful. When dealing with electricity, second chances are rare.