Abstract: A voltage sensor comprises a voltage divider configuration with first and second circuit portions providing first and second impedances. The first and second circuit portions are configured such that the temperature dependence of the second impedance matches the temperature dependence of the 5 first impedance within an operating temperature range. The impedance component of the second circuit portion and the impedance component of the first circuit portion are co-located with each other or otherwise located in one or more location that is subject to, in use, substantially the same temperature. The voltage sensor exhibits improved accuracy in comparison with voltage sensors without temperature compensation, and may also exhibit improved accuracy over temperature-0 compensated voltage sensors that rely on temperature measurement since temperature measurement can be a source of error.

Abstract: A circuit breaker includes a capacitive voltage sensor located within its insulating casing. The voltage sensor includes a capacitor located between the terminals of the circuit breaker adjacent a low potential surface provided by a coil of a current sensor. The capacitor is dome shaped. The voltage sensor does not appreciably increase the size or weight of the circuit breaker and is reliable and accurate.

Abstract: A vacuum circuit breaker 10 comprising a vacuum interrupter 12 coupled between upper 18 and lower 20 terminals and being operable to make or break an electrical connection between the upper and lower terminals. The circuit breaker has a body 22 formed from electrically insulating material, the vacuum interrupter being located in an internal chamber of the body. The lower terminal 20 comprises a hollow body 26 that forms part of the internal chamber and which is shaped and dimensioned to allow the vacuum interrupter 12 to pass through it. An electrical connector device 50 has a movable part 52 that is connected to the movable contact and an annular fixed part 54 that is connected to the lower terminal 20. The movable part 52 is connected to the first part 54 by flexible connectors 56, and has a socket (58) for engaging an electrical connector 60 of the vacuum interrupter 12. A pulling rod 16 is coupled to the movable contact via the electrical connector 60.

Abstract: A vacuum circuit breaker comprising a vacuum interrupter (12) coupled between upper (18) and lower (20) terminals and being operable to make or break an electrical connection between the upper and lower terminals. The circuit breaker has a body 22 formed from electrically insulating material, the vacuum interrupter being located in an internal chamber of the body. The circuit breaker body is arranged to provide an isosceles triangle between the upper (C) and lower (A) terminal connection interfaces. This allows the same design of both upper and lower external connectors 80, 82. A pulling rod (16) coupled to the vacuum interrupter comprises a core (70) of heat-resistant plastic co-moulded with a shell (72) formed from impact resistant plastic.

Abstract: A vacuum circuit breaker 10 comprising a vacuum interrupter 12 coupled between upper 18 and lower 20 terminals and being operable to make or break an electrical connection between the upper and lower terminals. The circuit breaker has a body 22 formed from electrically insulating material, the vacuum interrupter being located in an internal chamber of the body. The lower terminal 20 comprises a hollow body 26 that forms part of the internal chamber and which is shaped and dimensioned to allow the vacuum interrupter 12 to pass through it. An electrical connector device 50 has a movable part 52 that is connected to the movable contact and an annular fixed part 54 that is connected to the lower terminal 20. The movable part 52 is connected to the first part 54 by flexible connectors 56, and has a socket (58) for engaging an electrical connector 60 of the vacuum interrupter 12. A pulling rod 16 is coupled to the movable contact via the electrical connector 60.

Abstract: A vacuum circuit breaker comprising a vacuum interrupter (12) coupled between upper (18) and lower (20) terminals and being operable to make or break an electrical connection between the upper and lower terminals. The circuit breaker has a body 22 formed from electrically insulating material, the vacuum interrupter being located in an internal chamber of the body. The circuit breaker body is arranged to provide an isosceles triangle between the upper (C) and lower (A) terminal connection interfaces. This allows the same design of both upper and lower external connectors 80, 82. A pulling rod (16) coupled to the vacuum interrupter comprises a core (70) of heat-resistant plastic co-moulded with a shell (72) formed from impact resistant plastic.