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Blog Entry# 2283664
Posted: May 19 2017 (22:32)
1 Responses
Last Response: Jun 01 2017 (19:03)
1 Responses
Last Response: Jun 01 2017 (19:03)
Why do you sometimes see sparks on the catenaries?
This phenomenon is part of the normal functioning of the train, causing only very minor wear
to material and presenting no risk for passengers. How can it be explained?
The sparking from catenaries can be explained by the flexibility of the (spring loaded) pantograph and the catenary (wire), sometimes causing the pantograph to separate from...
more...
This phenomenon is part of the normal functioning of the train, causing only very minor wear
to material and presenting no risk for passengers. How can it be explained?
The sparking from catenaries can be explained by the flexibility of the (spring loaded) pantograph and the catenary (wire), sometimes causing the pantograph to separate from...
more...
It occurs when voltage between conductors rises high enough that the air insulation between them suddenly breaks down and becomes ionized (and therefore, electrically conductive). This instantly results in a low resistance conductive path through the air, followed by a large increase in electrical current. The result is an instant, bright flash. Arc flashes are initiated by excessive voltage, but the arc, once initiated, is sustained not by high voltage, but by the resulting high current.
Arc flashes can occur directly through the air that lies between high voltage conductors, or even across the surface of an insulator that separates two conductors.
Arc flashes can occur directly through the air that lies between high voltage conductors, or even across the surface of an insulator that separates two conductors.