Abstract: An electrical protection unit A including a main conductor and, for each main conductor, a current limiter device connected in series with the main conductor to limit the current when a current or temperature threshold is exceeded, the limiter device including an element made of a material having a positive temperature coefficient, called PTC, and being capable of controlling a device for tripping the mechanism M for opening the contacts of the protection unit D, to cause the opening of the contacts of the unit when the threshold is exceeded leading to a change of state of the element between a low resistance state and a high resistance state. The PTC element includes the trip device, in such a way that this element itself provides the functions of fault current limitation and of tripping the mechanism for opening the contacts.

Abstract: A device comprises elements for measuring current, the elements being housed in a casing. The casing includes a first portion and a second portion made of plastic, welded to each other, which together define a housing for receiving the measuring elements. The first portion is opaque in order to absorb a laser beam for welding the portions, and the second portion is transparent in order to let the laser beam pass. The process for manufacturing the device includes a fitting step in which the measuring elements are fitted into the casing and an assembly step in which the portions of the casing are joined together using a laser welding process.

Abstract: A sensor for measuring current of the Rogowski-torus type including a carrier made of a magnetic materials and a secondary winding wound on the carrier in order to deliver an electrical signal representative of a current flowing in a conductor passing through the interior of the torus. The carrier is made essentially of a moulded rigid plastic material and includes at least one exterior recess distributed over the length of the body of the carrier. The recess includes at least two grooves that are separated by a partition. The protecting and measuring device and the electric circuit breaker include such a current sensor.

Abstract: An electrical protection unit A including a main conductor and, for each main conductor, a current limiter device connected in series with the main conductor to limit the current when a current or temperature threshold is exceeded, the limiter device including an element made of a material having a positive temperature coefficient, called PTC, and being capable of controlling a device for tripping the mechanism M for opening the contacts of the protection unit D, to cause the opening of the contacts of the unit when the threshold is exceeded leading to a change of state of the element between a low resistance state and a high resistance state. The PTC element includes the trip device, in such a way that this element itself provides the functions of fault current limitation and of tripping the mechanism for opening the contacts.

Abstract: A method for treating a surface of a wall, that can reduce conductivity thereof, the surface being located in a first area located near a second area in which an electric arc is likely to occur in an electrical protection apparatus, the first area constituting an area for recondensing cutting residue. The method includes micro-texturizing the surface to promote inhomogeneity in recondensation of cutting residue, by growing deposits of the residue on the surface to create islands of residue and thus to restrict conductivity of the resulting deposit.

Abstract: A sensor for measuring current of the Rogowski-torus type including a carrier made of a magnetic materials and a secondary winding wound on the carrier in order to deliver an electrical signal representative of a current flowing in a conductor passing through the interior of the torus. The carrier is made essentially of a moulded rigid plastic material and includes at least one exterior recess distributed over the length of the body of the carrier. The recess includes at least two grooves that are separated by a partition The protecting and measuring device and the electric circuit breaker include such a current sensor.

Abstract: A method for treating a surface of a wall, that can reduce conductivity thereof, the surface being located in a first area located near a second area in which an electric arc is likely to occur in an electrical protection apparatus, the first area constituting an area for recondensing cutting residue. The method includes micro-texturizing the surface to promote inhomogeneity in recondensation of cutting residue, by growing deposits of the residue on the surface to create islands of residue and thus to restrict conductivity of the resulting deposit.

Abstract: A device comprises elements for measuring current, the elements being housed in a casing. The casing includes a first portion and a second portion made of plastic, welded to each other, which together define a housing for receiving the measuring elements. The first portion is opaque in order to absorb a laser beam for welding the portions, and the second portion is transparent in order to let the laser beam pass. The process for manufacturing the device includes a fitting step in which the measuring elements are fitted into the casing and an assembly step in which the portions of the casing are joined together using a laser welding process.

Abstract: A protected transformer system and method are disclosed. The protected transformer system uses positive temperature coefficient resistive devices. The system can comprise a transformer and a positive temperature coefficient device. The transformer has a primary and a secondary winding. The secondary winding has a housing, a first terminal, a second terminal, and an insulated covering. The positive temperature coefficient device is connected to the first terminal of the secondary winding. The positive temperature coefficient device mounted in the housing. The positive temperature coefficient device has a first and second side. The first side of the positive temperature coefficient device is mounted between 0.2 mm 0.4 mm from the secondary winding. The second side of the positive temperature coefficient device is mounted between 1 mm and 5 mm from the secondary winding. The insulated covering is between the first side of the positive temperature coefficient device and the secondary winding.

Abstract: An electrical switch device with separable contacts is provided with a shunt conductor adapted to receive one end of the arc that is struck when the contacts separate after it has jumped a dielectric gap. The shunt conductor determines an interim arc current path in which is a current limiter device.

Abstract: A contact maker-breaker is disclosed in which the power contacts are associated in series with a superconducting element which is controlled by a heating element and which is structured so as to have a very high resistance following its controlled transition from the superconducting state to the normal state in response to a closing or opening order or following its intrinsic transition from the superconducting state to the normal state in response to a fault current, so that closing and opening of the power contacts takes place on the same leak current of a very low value.