Why doesn't rain on the superstructure at an electric sub station conduct electricity back to the frame?

Answer 1

Excellent question.

Electrical transmission systems, like the substations and transmission wires, are indeed exposed to the elements. But, depending on the voltage/current carried, they are built with suitable nonconducting materials around the sources of electricity to insulate (isolate) the electricity from the support structures. There is a "gap" of nonconducting material between the voltage side and the support side.

All is well and good when it is dry, but what about when it's raining or snowing and the water streaks down across the gap from the electricity carrying parts to the framework or support?

Well, as one answerer pointed out, fresh water is not that good a conductor. In fact, that's why we usually add some sort of salt (NaCl for example) when conducting water/electricity experiments in a lab. The salt then carries the current via its ions (e.g., Na+ Cl-)...other ionizing salts will also do the job.

So, when the rain/snow is pure, the combination of insulation and lack of conductivity keeps the circuit across the gap between the support and the electrified parts from closing. But, as the not infrequent blowouts of stations during storms will attest, this does not always work.

Rust, for example, can and has caused water streaks to become conductors...zap. Thus, older stations are more likely to fail. And, of course, winds along with the rain can blow conducting objects (like wires) across the wire-support bridge, close the gap between the two, and, again...zap.

Answer 2

1st: Rain is made up of pure distilled water, which in turn has a very poor electrical conductivity.
2nd: Every risk of electrical shock has been offset by isolators installation at the design stage of any superstructure.

Answer 3

living close to that substation is precisely as volatile as utilising and strolling and living below the lines that feed power to it and grant that power at a discounted voltage to you. The voltage on all those skinny overhead cables that crisscross city which you on no account pay interest to is the comparable because of the fact the substation voltage, and that they on no account injury everyone (till they get broken) so i does no longer subject approximately it. This by skill of ways is a somewhat diverse subject matter than the scare of living below the extensive long distance transmission pylons with the long spans of drooping cable, those lines perform at a hundred,000 volts and above. The substation voltage is going to be interior the low 1000's and you in basic terms could desire to save young babies from mountain climbing fences and firing B-B weapons and so on around those.

Answer 4

It has to be the huge size of the insulators. The distance to ground is too large even for high voltage to jump. Water isn't as good a conductor as people think either.

Answer 5

It does - in theory. But water is not as good a conductor as we're led to believe; water on an insulator from the high-voltage conductor to ground cannot carry enough current to cause a short to ground.

Answer 6

no this is a very good question that I cant answer and would keep an eye on this one to see the answer thanks for asking the question