What is the NEUTRAL ZONE IN OVERHEAD ELECTRIC TRACTIONS AND WHY IT IS THERE?

Question

AN ELECTRIC LOCOMOTIVE WHICH WAS HAULING NEARLY 15 CARS STOPPED WHEN A PERSON PULLED AN ALARM CHAIN . IT COULD NOT START AS THE ELECTRIC LOCOMOTIVE EXACTLY STOPPED IN THE NEUTRAL ZONE AND PEOPLE HAD TO GET DOWN AND PUSH THE CARS TO MAKE THE LOCOMOTIVE MOVE AWAY FROM THE NEUTRAL ZONE. AS SOON AS IT EXITED FROM THE NEUTRAL ZONE THE LOCOMOTIVE GOT BACK THE POWER. i WANT TO KNOW WHY THERE SHOULD BE NEUTRAL ZONE AND WHETHER IT IS ESSENTIAL FOR THE FUNCTIONING OF ELECTRIC TRACTION.

Answer 1

That's a circuit break.   That's how you separate one electrified section from another.

You know your house has multiple fuses or circuit breakers.  That way if you pop a circuit breaker in the kitchen, it doesn't kill the whole house.   It doesn't even kill your refrigerator or your lights.  They're on separate circuits.

Same with the railroad.  Different sections of track are on separate circuits, so that a problem in one section won't kill the whole railroad.

Where the circuits meet each other, there has to be some distance of insulation so the circuits don't "short out".   The train was just unlucky and stopped right on that insulation!  Whoops!

For city streetcars and trolley buses, there are often symbols painted on the street, to tell the driver where a circuit break is, so he knows not to stop there.   In San Francisco, they are yellow dots.

Now, most trains have 2 pantographs, and that's a reason why.  He should have been able to just "put up the other pantograph" and had power again.

Answer 2

i've never heard the term, but it's obviously a dead zone.

there are electric buses in San Francisco, and sometimes their wires cross.

when that happens, you have the situation where a + wire crosses a - wire, and you surely don't want them to touch.

so there is a dead zone where they cross.

i'd not think that trains have the same problem, since there is typically only a single wire above, and the tracks are the second half of the circuit.  obviously it does happen in some cases though.  in addition, most electric engines have 2 scissors, and i'd think that they'd raise the 2nd to get power.  just shows you how much i don't know.

btw, the trolley bus system in San Francisco uses 600 volts DC.  quite a system.  i know because many years ago, a hotel i stayed in used the trolley system electricity to power their elevator.

Answer 3

I imagine the neuteral zone plays a part in the electrical distribution system....

This would probably play a nessary part in making the transmission of electricity over long distances for the train more possible.

This is as high voltage 3 phase systems have a positive neuteral and negative

I imagine there may be a small gaps along the wires transmission lines where it is a neuteral zone to stop the wire getting too hot and expanding and breaking, so they all run independantly of each other... and as they dont expect trains to be stopping on that part of the track.

Answer 4

The Neutral Zone is a portion of track on an electric railway that does not have any power running through it. It is there to allow railway workers a portion of track to operate from (if there is a problem) until they can halt rail traffic and take the power down.

Answer 5

There has to be a neutral zone if the train runs on tracks that have had their polarity switched, otherwise the tracks would short out.

Answer 6

CHAPTER XVII

WORKING OF TRAINS ON ELECTRIFIED

SECTIONS OF RAILWAYS

http://www.southernrailway.org/tpjsec/GR...

Happy reading.