Switching device for the interruption of fault currents

A switching device for the interruption of a fault current, comprising:

• a housing including first and second electrical connectors for connection in the path of an electrical conductor carrying a single current phase, said housing being associated solely with the single current phase, said housing having a first chamber, a second chamber and a partition separating said first and second chambers;
• a vacuum switching chamber disposed in said first chamber;
• a stationary switch contact and a movable switch contact disposed in said vacuum switching chamber;
• a shaft connected to said movable switch contact and penetrating said partition toward said second chamber;
• first connection means disposed in said first chamber for connecting said stationary switch contact to said first electrical connector;
• second connection means disposed in said second chamber for creating a displaceable contact connection between said shaft and said second electrical connector for electrically connecting said movable switch contact with said second electrical connector;
• a current transformer disposed in said second chamber adjacent said partition and including a toroidal core surrounding said shaft of said movable switch contact, a secondary winding mounted on said toroidal core, and a primary circuit connected between said first and second electrical connectors for conducting the single current phase and inducing a corresponding current in said secondary winding, said shaft constituting said primary circuit of said current transformer;
• magnet actuator means disposed in said second chamber following said current transformer in a direction away from said partition and electrically connected in a circuit with said secondary winding of said current transformer, said magnet actuator including a toroidal coil surrounding said shaft, a ferromagnetic body at least partially enclosing said toroidal coil and defining an air gap, and a displaceable magnet armature disposed in said air gap, said magnet actuator means having an inactive state and an actuated state and being responsive to a fault current in said primary circuit of said current transformer, by way of the corresponding current in said secondary winding, for changing from the inactive state to the actuated state;
• latch means disposed in said second chamber following said magnet actuator means in the direction away from said partition, said latch means coupled to said movable switch contact for latching said movable switch contact in a closed position with respect to said stationary switch contact and for being unlatched in response to a change to the actuated state of said magnet actuator means for moving said movable switch contact to an open position relative to said stationary switch contact;
• a turn-off spring disposed in said second chamber, for storing a spring force and operatively associated with said latch means for causing said latch means, under influence of the spring force, to separate said movable switch contact from said stationary switch contact when said latch means becomes unlatched;
• and
• reset means operatively connected to said latch means for causing said latch means to latch said movable switch contact in the closed position and for restoring the spring force of said turn-off spring after said latch means is unlatched in response to a fault current.

A switching device for the interruption of a fault current, comprising:

• a housing including first and second electrical connectors for connection in the path of an electrical conductor carrying a single current phase, said housing being associated solely with the single current phase, said housing having a first chamber, a second chamber and a partition separating said first and second chambers;
• a vacuum switching chamber disposed in said first chamber;
• a stationary switch contact and a movable switch contact disposed in said vacuum switching chamber and connected;
• a shaft connected to said movable switch contact and penetrating said partition toward said second chamber;
• first connection means disposed in said first chamber for connecting said stationary switch contact to said first electrical connector;
• second connection means disposed in said second chamber for creating a displaceable contact connection between said shaft and said second electrical connector for electrically connecting said movable switch contact with said second electrical connector, said displaceable contact connection including a sliding contact connected to said second electrical connector;
• a current transformer disposed in said second chamber, said current transformer including a secondary winding, and a primary circuit connected between said first and second electrical connectors for conducting said single current phase and inducing a corresponding current in said secondary winding;
• magnet actuator means disposed in said second chamber and electrically connected in a circuit with said secondary winding of said current transformer, said magnet actuator means having an inactive state and an actuated state and being responsive to a fault current in said primary circuit of said current transformer, by way of the corresponding current in said secondary winding, for changing from the inactive state to the actuated state;
• latch means disposed in said second chamber, coupled to said movable switch contact for latching said movable switch contact in a closed position with respect to said stationary switch contact and for being unlatched in response to a change to the actuated state of said magnet actuator means for moving said movable switch contact to an open position relative to said stationary switch contact;
• a turn-off spring disposed in said second chamber, for storing a spring force and operatively associated with said latch means for causing said latch means, under influence of the spring force, to separate said movable switch contact from said stationary switch contact when said latch means becomes unlatched;
• and
• reset means operatively connected to said latch means for causing said latch means to latch said movable switch contact in the closed position and for restoring the spring force of said turn-off spring after said latch means is unlatched in response to a fault current.

A switching device for the interruption of a fault current forming a combination with a power circuit breaker, said switching device, comprising:

• a housing including first and second electrical connectors for connection in the path of an electrical conductor carrying a single current phase, said housing being associated solely with the single current phase;
• a vacuum switching chamber disposed in said housing;
• a stationary switch contact and a movable switch contact disposed in said vacuum switching chamber and connected, respectively, to said first and second electrical connectors;
• a current transformer disposed in said housing, said current transformer including a secondary winding, and a primary circuit connected between said first and second electrical connectors for conducting the single current phase and inducing a corresponding current in said secondary winding;
• magnet actuator means disposed in said housing and electrically connected in a circuit with said secondary winding of said transformer, said magnet actuator means having an inactive state and an actuated state and being responsive to a fault current in said primary circuit of said current transformer, by way of the corresponding current in said secondary winding, for changing from the inactive state to the actuated state;
• latch means disposed in said housing, coupled to said movable switch contact for latching said movable switch contact in a closed position with respect to said stationary switch contact and for being unlatched in response to a change to the actuated state of said magnet actuator means for moving the movable switch contact to an open position relative to said stationary switch contact;
• a turn-off spring for storing a spring force and operatively associated with said latch means for causing said latch means, under influence of the spring force, to separate said movable switch contact from said stationary switch contact when said latch means becomes unlatched;
• and
• reset means operatively connected to said latch means for causing said latch means to latch said movable switch contact in the closed position and for restoring the spring force of said turn-off spring after said latch means is unlatched in response to a fault current,
• said combination including means operatively connected between said movable switch contact and said power circuit breaker to open said power circuit breaker in response to a movement of said movable switch contact which separates said movable and stationary switch contacts.