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#safetytips

Safety Moment, Electrical chock hazard, How to Survive Step Potential when a high voltage line fails on the ground? Why are stones used in power station? Why is gravel used in transformer yard? What is the purpose of gravel in substation? Why Crushed Rock is Laid in Substations? Purpose of Stones/Gravel in the Power Substations? Step potential is the voltage difference between the two feet of a person standing near an energized, grounded object. This invisible hazard can be deadly for anyone in the vicinity of a downed power line. How step potential happens When a power line contacts the earth, it carries electrical current into the ground. If the voltage is strong enough, the current will spread out from the point of contact. Voltage will be highest at the point of contact and will diminish with distance from that point. (Voltage levels may vary with ground conditions and the conductivity of the soil.) If you walk across this energized area, the voltage between your feet will differ. Electricity will use your legs as a path to travel from an area of higher voltage to an area of lesser voltage, resulting in electrocution or serious injury. The shuffle technique is key If you are in the vicinity of a downed power line, you must take small, shuffling steps with your feet close together in contact with the ground at the same time, all the time. Do not take large steps and do not allow your heels to pass your toes. This ensures both feet remain in areas of similar voltage. Continue shuffling until you are a safe distance away: at least 30 feet away from a downed distribution line and at least 100 feet away from a downed transmission line. These clearance distances are minimums: always use the maximum possible clearance.