A switch includes: a first contact and a second contact placed on an operation axis and facing each other; an urging part that urges the second contact to a first contact side; and a second magnetic material part that engages with the second contact to restrict the second contact from moving to the first contact side. The switch also includes: a conductor part that passes current when an arc is formed between the first contact and the second contact; and a first magnetic material part that surrounds the conductor part. When current flows through the conductor part, the second magnetic material part is disengaged from the second contact.

An earthing switch circuit is provided and is connected to a direct current (DC) link including a positive terminal and a negative terminal having capacitance or energy storage capability. The earthing switch circuit includes a dynamic braking circuit having a single or plurality of dynamic braking (DB) switches, and at least one dynamic braking (DB) resistor disposed between the plurality of DB switches, and an earthing switch connected between the DB circuit and ground. The at least one DB resistor dissipates energy thermally when performing a dynamic braking operation and simultaneously decreases in-rush current for the earthing switch circuit upon closure of the earthing switch.

A three-position disconnector switch includes a platform, a power in contact, a power out contact, an earthing contact, and a piston. In a first position, the piston contacts the power out contact and the power in contact. In a second position, the piston contacts the power out contact. In a third position, the piston contacts the power out contact and the earthing contact. The piston moves along an axis to transition between the different switch positions. The power in contact is mounted to the platform, the power out contact is mounted to the platform, and the earthing contact is mounted to the platform.

An apparatus for use in a power delivery system, the apparatus comprising: a DC circuit breaker having first and second terminals and configured to automatically switch from a closed state to an open state during an overcurrent condition; a disconnector switch in series with the DC circuit breaker, the disconnector switch having a first terminal for connecting to a first polarity terminal of a DC power supply, a second terminal for connecting to a second polarity terminal of the DC power supply and a common terminal connected to the first terminal of the DC circuit breaker, the disconnector switch having at least a first position in which the first terminal is connected to the common terminal and a second position in which the second terminal is connected to the common terminal; and an interlock mechanism coupled to the DC circuit breaker and the disconnector switch, the interlock mechanism configured to disable the DC circuit breaker from automatically switching from the closed state to the open state during the overcurrent condition when the disconnector switch is in the second position.

A switch for a medium voltage or high voltage switchgear includes: a first fixed contact; a second fixed contact; a moveable contact; at least one flexible link; and a contact drive. In an on state of the switch, the moveable contact is in a position that connects the first fixed contact to the second fixed contact. In an off state of the switch, the moveable contact is in a position where the first fixed contact is not connected to the second fixed contact. The at least one flexible link is connected to the moveable contact. The at least one flexible link engages with the contact drive. The contact drive pulls the moveable contact via the at least one flexible link and pushes the moveable contact via the at least one flexible link. Activation of the contact drive in a first mode moves the moveable contact.

An electrical assembly including a grounding mechanism and an electrical device, the grounding mechanism including a support longitudinal member and a switch contact member, the switch contact member arranged in or on the support longitudinal member, the switch contact member configured to be connected in use to ground, the electrical device including an electrical terminal, wherein the support longitudinal member is configured to be slidable between: a first position in which the switch contact member is separated from the electrical terminal so that the switch contact member is electrically disconnected from the electrical device and a second position in which the switch contact member is in contact with the electrical terminal so that the switch contact member is electrically connected to the electrical device.

A switch includes: a first contact and a second contact placed on an operation axis and facing each other; an urging part that urges the second contact to a first contact side; and a second magnetic material part that engages with the second contact to restrict the second contact from moving to the first contact side. The switch also includes: a conductor part that passes current when an arc is formed between the first contact and the second contact; and a first magnetic material part that surrounds the conductor part. When current flows through the conductor part, the second magnetic material part is disengaged from the second contact.

A circuit breaker/disconnector apparatus for use in a power delivery system comprises a unidirectional DC circuit breaker which has a first terminal and a second terminal and is configured to automatically open during an overcurrent condition in a forward direction and to remain closed independent of current level in a reverse direction. A disconnector switch is in series with the circuit breaker. The disconnector switch has a first terminal for connecting to a first polarity connector of a power supply, a second terminal for connecting to a second polarity connector of the power supply and a common terminal connected to the first terminal of the circuit breaker. The disconnector switch has at least a first position in which the first terminal is connected to the common terminal and a second position in which the second terminal is connected to the common terminal. The second polarity connector of the power supply may be coupled to a track of a transport system and the second polarity connector of the power supply may be coupled to a live overhead cable or live third rail of a transport system. The apparatus can be used to safely ground the live cable or third rail when in a maintenance condition.

A disconnector device is connectable to pole-mounted equipment in a power grid. The disconnector device is activated in case of an overload condition, thereby disconnecting the pole-mounted equipment. The disconnector device comprises a passive radio device to be enabled via an incoming radio signal. The passive radio device, upon being enabled, transmits, in at least one state of the disconnector device, an indicator radio signal indicative of the respective state of the disconnector device, the state being one of an activated state and a deactivated state of the disconnector device.

A grounding switch for grounding a high voltage cable in underground switchgear. The switch includes a solid insulation housing and a fixed electrode extending into one end of the housing and being encapsulated in the solid insulation housing. The switch also includes a ground electrode positioned at an opposite end of the housing from the fixed electrode, an air gap formed in the solid insulation housing between the fixed electrode and the ground electrode, and a movable electrode slidable positionable within the air gap to electrically connect and disconnect the fixed electrode to and from the ground electrode. An annular shielding electrode having a ridge is electrically coupled to the fixed electrode proximate the air gap, and shapes an electric field generated by the fixed electrode to be mostly confined within the solid insulation housing.