Arc shorting device
AssigneeNorthern Engineering Industries plc
InventorsPeter Headley, Thomas Kelsey, John Murdy
Life of this patent
Estimating the term…
Abstract
In or for a fluid-filled metal-clad switchgear an automatically-operating device for short-circuiting an internal arc in the earthed metal enclosure comprises a piston movable in a cylinder mounted on the enclosure wall, with a rod projecting towards the interior space filled with insulating medium. A pipe or other means connects the space to the cylinder at the remote side of the piston, so that on occurrence of an internal arc in the enclosure the rapid pressure rise creates a pressure differential across the piston to drive it and the rod inwardly and cause the rod to engage the high-voltage conductor and short-circuit the arc to the earthed enclosure. The piston is held normally by a spring or by breakable pegs.
Claims9
An arc-shorting device in high-voltage metal clad switchgear comprising a conductor within an enclosure containing fluid insulating medium, which device comprises a contact movable to a position to interconnect said conductor electrically to said enclosure and piston-and-cylinder mechanism the cylinder of which communicates with the interior of said enclosure, said mechanism being operable in response to a rise in pressure in said fluid medium upon occurrence of an arc in said enclosure to move said contact to said position.
An arc-shorting device in high-voltage metal-clad switchgear which device comprises means for mounting said device on an enclosure of said switchgear containing fluid insulating medium, said device further comprising a cylinder, a piston movable in said cylinder and having first and second sides, a contact advanceable by said piston from a first retracted position to a second advanced position in which the contact engages a conductor within said enclosure to connect the conductor electrically to said enclosure, first means establishing communication between the interior of said enclosure and the interior of said cylinder at said first side of said piston, second means defining a space, third means establishing communication between said space and the interior of said cylinder at said second side of said piston, and restraint means to hold said piston in said first position, whereby rise in pressure in said fluid medium upon occurrence of an arc in said enclosure causes a pressure difference across said piston to overcome said restraint means whereupon said piston advances said contact to said second position.
An arc-shorting device in high voltage metal-clad switchgear which device comprises means for mounting said device on an enclosure of said switchgear containing a fluid insulating medium, said device further comprising a cylinder, a piston movable in said cylinder and having first and second sides, a contact in the form of a rod connected at one end to said piston at said second side thereof and advanceable by said piston from a first retracted position to a second advanced position in which the contact rod engages a conductor within said enclosure to connect the conductor electrically to said enclosure, a pipe establishing communication between the interior of said enclosure and the interior of said cylinder at said first side of said piston, a housing defining a space about said cylinder, vents establishing communication between said space and the interior of said cylinder at said second side of said piston, and restraint means to hold said piston in said first position, whereby rise in pressure in said fluid medium upon occurrence of an arc in said enclosure causes a pressure difference across said piston to overcome said restraint means whereupon said piston advances said contact rod to said second position.
An arc-shorting device in high-voltage metal-clad switchgear which device comprises means for mounting said device on an enclosure of said switchgear containing fluid insulating medium, said device further comprising a first cylinder, a piston movable in said cylinder and having first and second sides, a contact in the form of a rod connected at one end to said first piston at said second side thereof and advanceable by said piston from a first retracted position to a second advanced position in which the contact rod engages a conductor within said enclosure to connect the conductor electrically to said enclosure, a second cylinder defining a first space about said first cylinder, vents establishing communication between the first space and the interior of said first cylinder at said second side of said piston, a housing containing said cylinders and defining a second space about said second cylinder establishing communication with the interior of said first cylinder, an annular member through which said contact rod is advanceable establishing communication between the interior of said enclosure and said second space, and restraint means to hold said piston in said first position, whereby rise in pressure in said fluid medium upon occurrence of an arc in said enclosure causes a pressure difference across said piston to overcome said restraint means whereupon said piston advances said contact rod to said second position.
Dependencies are inferred from the claim text.