February 28, 2020 for 4:36 AM It is said that the voltage of an arc is 440 V per the arcing distance, specified in one of the comments made in this particular post. The actual arcing distance has a lot to do with the altitude, the pressure and the humidity of the circuits line. Which may be over 100 miles. It refers to the capacitance coupling to grout. But you must remember this is a distributed, capacitance ground, not a lump capacitance. Therefore, the potential danager has to do with how current is on the line, and not necessarily the insulation protection from the human body to earth. If the arc happens to jump to his body and arcs across the body - well that’s gonna be a lot of power crossed that portion of his body. For example, the average line current is roughly 2 Amps, so that’s the basis of the capacity currents testing for C testing to statistically prove a class capacitive switching of energize lines, to give some basis of whether it should have a rating. The topic of discussion takes up a huge percentage of the committees time, and we’re off to talk about it to the point where the cows come marching. The reason for this is that we don’t always know the frequency of the capacitance of the circuit. Most of it is quite high, and therefore a discharge across the body tends to go around his body even without a properly design PPE suit. For the higher voltage workers, they definitely are going to be wearing a properly design Faraday cage PPE suit. So while Doug has an audience, the roads are much more intuitive on on this because they can feel the electromagnetic energy, and they rarely land on powerlines that have a lagging or leading PF, or or any powerline it’s much above 34 KV. coupling capacitance of the line, increases when the power factor is not at Unity, and or intuitively it increases with Voltage. Smarter humans wear PPE know how to apply it and therefore avoid electrical accidents. Utilities that do not understand these details have a higher rate of incidence of death - electrical workers have some of the most dangerous jobs in the planet.
USMC Veteran-Electrical Safety SME-CESCP-EHS and Risk Management. Lead NFPA 70 E Trainer. OSHA 10 and 30 Authorized Outreach Trainer.
Spicy!! Mad respect to our linemen out there! I can only imagine what this type of energized work would be like.
