Are automatic reclosers used in transit applications? Or if a fault is detected do they need to be reset manually?
EnzoampsIn my scenario, the loco was not on its side, it was sitting on the ties, as stated. A simple derailment, not a major wrec
If an engine's wheels drops off the rails, the frame, pilot, body, something is usually still against the rails.
It's been fun. But it isn't much fun anymore. Signing off for now.
The opinions expressed here represent my own and not those of my employer, any other railroad, company, or person.t fun any
In my scenario, the loco was not on its side, it was sitting on the ties, as stated. A simple derailment, not a major wreck. My question was/is a technical one, not a procedural one, not wondering what they would do in response to the situation. Yes, they should immediately drop the pantograph, and so on. I wouldn't think dropping six inches would be enough to lose pantograph contact with the catenary.
However, in the moment before the alert engineer does drop the pantograph, flips the breaker, and what-not, would the train frame or wheels represent shock hazard to anyone touching it while themselves on the ground?
Would all this ever happen? Likely not, but that isn't my point. I am curious about the electrical nature of the system.
beaulieuThere are a lot of assumptions in that, The first would be how would the pantograph still be in contact with the wire if the locomotive was on its side. second would be that the crew would not open the main circuit breaker.
When you're in that bad of a pileup in electrified territory, the major concern is that poles are knocked over and you have wires laying on the train. Yes, everything and its cousin should trip and there should be no power, but you never assume.
Both measures are standard procedure in any derailment. With third rails, open the line-switch replaces lowering the pantograph.
There are a lot of assumptions in that, The first would be how would the pantograph still be in contact with the wire if the locomotive was on its side. second would be that the crew would not open the main circuit breaker. The third would be how would the pantograph be undamaged as damaging the pantograph causes it to lower, as the pantograph is held up by air pressure through the pantograph head to cause the pantograph to lower in case of damage without any action by the crew. And finally that assumes that the Overheads circuit breaker wouldn't trip sensing a ground fault. Yes all that could happen and yes just like any overhead wiring you could have live power on a locomotive lying on the ground but it isn't likely. Never the less it is a good idea to call the railroad emergency number if you see an electric locomotive lying on its side.
In that case the engineer would make a quick call to dispatch power board in the meanwhile ( drop the pan.
OK, as I understand electric locomotives, the single wire catenary frovides current at a high voltage for the locomotive. As I further understand it, the rails act as the return or ground for the circuit. Electricity always needs a circuit. If that is not correct, please fix me.
Hypothetically, if the electric loco winds up on the ground - ie wheels on the ties, not touching the rails - and the pantograph is still in contact with the catenary, would the wheels and/or chassis be electrically "hot"? The wheels would no longer be grounded via the rails. Without a complete circuit, no current would flow through the system so there would be no voltage drop. (Ohm's Law) Meaning the full thousands of volts might be present on the wheels, waiting for some unfortunate soul to touch them.
Make any sense?
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