A fault protection system for providing protection from fault current for components and devices on a lateral line proximate to a distribution transformer in a power distribution network. The system includes a single-phase recloser having a vacuum interrupter that is controlled by a controller. In one embodiment, the recloser has an insulating body that is molded in combination with an insulating body of a bushing that is connected to the distribution transformer. In this embodiment, the controller can be powered by a current transformer within the recloser. In another embodiment, the recloser is mounted to a utility pole separate from the distribution transformer, where the controller is powered by the low voltage side of the transformer and the current transformer is eliminated. An isolated power supply is provided between the transformer and the controller to provide voltage isolation.

A system for an electrical power distribution network includes an electrical apparatus configured to monitor or control one or more aspects of the electrical power distribution network, the electrical apparatus including a contact switch configured to open and close. The system also includes an input apparatus. The input apparatus includes an impedance module; and an input interface electrically connected to the impedance module and to the contact switch of the electrical apparatus. The input interface is configured to have one of a plurality of input impedances, the plurality of input impedances include at least a first input impedance and a second input impedance that is lower than the first input impedance, and the input interface has the second input impedance when the contact switch of the electrical apparatus is open. The input apparatus may include a plurality of leakage current detection modules.

Embodiments of the disclosure can include systems and methods for limiting transient over-voltages occurring across a circuit breaker. These embodiments include providing a middle tank portion. They further include providing a first portion coupled to a first side of the middle tank portion, and a second portion coupled to a second side of the middle tank portion. They further include providing a first high voltage terminal coupled to the first portion, and a second high voltage terminal coupled to the second portion. They further include providing a post insulator supported and extending from the middle tank portion. They further include providing a first surge arrester connecting the first high voltage terminal to a first connector extending from the post insulator, and a second surge arrester connecting the second high voltage terminal to a second connector extending from the post insulator.

Embodiments of the disclosure can include systems and methods for limiting transient over-voltages occurring across a circuit breaker. These embodiments include providing a middle tank portion. They further include providing a first portion coupled to a first side of the middle tank portion, and a second portion coupled to a second side of the middle tank portion. They further include providing a first high voltage terminal coupled to the first portion, and a second high voltage terminal coupled to the second portion. They further include providing a post insulator supported and extending from the middle tank portion. They further include providing a first surge arrester connecting the first high voltage terminal to a first connector extending from the post insulator, and a second surge arrester connecting the second high voltage terminal to a second connector extending from the post insulator.

A method of obtaining characteristic measurements K and of an electrical system comprising at least two terminals, the method comprising: injecting a reference voltage at a first of the at least two terminals; measuring a voltage at a second of the at least two terminals to provide a measured voltage, the second terminal being connected to earth; measuring a ratio of amplitude between the injected reference voltage and the measured voltage to provide a K value; and measuring a phase angle difference between the injected reference voltage and the measured voltage to provide an angle value .

A pole unit including a vacuum interrupter switch having a fixed contact extending into one end of a vacuum chamber and being electrically coupled to a first terminal, and a moving contact extending into an opposite end of the chamber. A sliding contact is rigidly coupled to the moving contact and slidably coupled to a second terminal. The pole unit also includes an electromagnetic actuator including a coil, a rod coupled to the sliding contact and a spring positioned against the rod. The pole unit further includes a transmitter coil and a receiver coil that are electromagnetically coupled, where the receiver coil is electrically coupled to the actuator and is electrically isolated from the transmitter coil. In this configuration, the interrupter switch, the actuator and the receiver coil are at a line potential and the transmitter coil is at ground potential.

A method and an apparatus for controlling a circuit breaker in an electrical energy supply network. A switching signal is generated by a protective or control device of the energy supply network and the switching signal is transmitted to a control unit of the circuit breaker. The control unit is caused to open the switching contacts of the circuit breaker upon reception of the switching signal. In order to ensure a switching operation which is as fast as possible even in those energy supply networks in which phases of the current to be switched by a circuit breaker which are free of zero crossings can occur, a current flowing through the circuit breaker is recorded and is checked for the occurrence of zero crossings. The transmission of the signal for opening the switching contacts is prevented until at least one zero crossing has been detected.

A switchgear or control gear includes: at least one first compartment; at least one second compartment; a plurality of main switchgear or control gear components including a main busbar system, a three position linear or rotational movement disconnector, a circuit breaker, and at least a first part of an insulated cable connection; and a plurality of auxiliary switchgear or control gear components including a disconnector drive and a circuit breaker drive. The plurality of main switchgear or control gear components are housed in the at least one first compartment. The plurality of auxiliary switchgear or control gear components are housed in the at least one second compartment. When one or more of the plurality of main switchgear or control gear components is energized, the at least one first compartment is hermetically sealable or maintainable at an internal air pressure greater than ambient air pressure.

A capacitive voltage sensor that has particular application to be molded into an insulating body of a switch. The voltage sensor includes an annular electrode assembly having a grounded electrode including an inner ring and an outer ring defining a space therebetween, and a sensing electrode positioned in the space and being substantially surrounded by the inner and outer rings. The body is formed around the electrode assembly and a cylindrical center conductor extends through the electrode assembly. Capacitive coupling is provided between the sensing electrode and the center conductor by one or more openings in the inner ring, such as a single round hole, a slot or a plurality of symmetrically disposed round holes or slots. The inner and outer rings can be attached at one end so that the grounded electrode is a single piece or the rings can be separate rings electrically coupled together by conductive screws.

A pole unit including a vacuum interrupter switch having a fixed contact extending into one end of a vacuum chamber and being electrically coupled to a first terminal, and a moving contact extending into an opposite end of the chamber. A sliding contact is rigidly coupled to the moving contact and slidably coupled to a second terminal. The pole unit also includes an electromagnetic actuator including a coil, a rod coupled to the sliding contact and a spring positioned against the rod. The pole unit further includes a transmitter coil and a receiver coil that are electromagnetically coupled, where the receiver coil is electrically coupled to the actuator and is electrically isolated from the transmitter coil. In this configuration, the interrupter switch, the actuator and the receiver coil are at a line potential and the transmitter coil is at ground potential.