Roughly how many amps can a high voltage power line produce (short circuit)?
ScottH, Sun Mar 05 2017, 02:20PMIf the hot wire of a 7,200v distribution power line were to contact the neutral wire (without safety features blowing/tripping), how many amps could potentially (*pun) flow?
I am also curious; Why don't the safety features blow/trip when a 7,200v hot wire is arcing to Earth after falling (even on a rainy day with wet soil)? Would as much current be flowing from hot to Earth compared to hot-->neutral (which is also at Earth potential)?
Re: Roughly how many amps can a high voltage power line produce (short circuit)?
Mads Barnkob, Mon Mar 06 2017, 07:20AM
Short answer: It all comes down to the impedance of the circuit that is shorted, long power lines have a resistance and if it long enough it will just look like a high load to the generator/transformer and fuses might take minutes or hours to overheat and burn. But this is much more complex than that, "minimum short circuit current" calculations are the industry standard to determine energy levels of short circuits and what has to be done to have it high enough to actually blow a fuse. Believe it or not, but a too low short circuit current is actually a dangerous situation :)
Long answer:
and
Mads Barnkob, Mon Mar 06 2017, 07:20AM
Short answer: It all comes down to the impedance of the circuit that is shorted, long power lines have a resistance and if it long enough it will just look like a high load to the generator/transformer and fuses might take minutes or hours to overheat and burn. But this is much more complex than that, "minimum short circuit current" calculations are the industry standard to determine energy levels of short circuits and what has to be done to have it high enough to actually blow a fuse. Believe it or not, but a too low short circuit current is actually a dangerous situation :)
Long answer:
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