A method of controlling an electromagnetic relay includes supplying a first voltage to an exciting coil to bring a movable terminal into contact with a fixing terminal; causing a coupling state determination unit to determine that a coupling failure is detected in a case where the movable terminal is not brought into contact with the fixing terminal and the electromagnetic relay is not turned on despite the supplying the first voltage to the exciting coil; and supplying a second voltage higher than the first voltage from a booster circuit to the exciting coil in a case where the coupling state determination unit determines that the coupling failure is detected. The second voltage is generated by boosting the first voltage by the booster circuit.

The present disclosure relates to a molded case circuit breaker. In accordance with one aspect of the present disclosure, a molded case circuit breaker for use in connection with a main busbar provided on a distribution board panel includes a power-source-side terminal provided to a front portion of a case and having a terminal assembly hole formed at an upper portion thereof; a base bus supporter comprising a connector protruding from a front surface thereof so as to engage with the main busbar installed on one side of the distribution board panel, the base bus supporter being coupled to an upper surface and a lower surface of the power-source-side terminal; an auxiliary cover plate coupled to an upper portion of the power-source-side terminal and provided with a temperature measurement hole communicating with the terminal assembly hole.

A circuit breaker includes a set of separable contacts moveable between a closed position and an open position, an operating mechanism configured to open the set of contacts, a conductor coupled to the set of contacts, a current transformer coupled to the conductor, and a trip circuit coupled to the operating mechanism and to the current transformer and configured to cause the operating mechanism to open the set of contacts when a current through the conductor exceeds a current threshold that is greater than a saturation threshold of the current transformer. The trip circuit is further configured to vary the current threshold during an interval following a closure of the set of the contacts and to provide a fixed current threshold thereafter.

The present invention relates to a main circuit part of a vacuum circuit breaker, and more particularly, to a main circuit part of a vacuum circuit breaker with a temperature sensor. The main circuit part of a vacuum circuit breaker with a self-powered temperature sensor assembly includes: a self-powered temperature sensor module; and a support bracket enclosing and supporting the self-powered temperature sensor module.

A monitoring method for an electrical energy transfer device which has a first phase conductor and a second phase conductor, includes the following steps: a temperature of the first phase conductor is compared with the temperature of the second phase conductor and a signaling is performed if there is a deviation between the temperatures. The electrical energy transfer device is, for this purpose, equipped at the first phase conductor with a first temperature sensor and at the second phase conductor with a second temperature sensor.

A method for estimating a property of an electrical switching device includes: detecting a movement of electrical contacts of the switching device beyond an opening threshold; measuring, for at least one phase of the electrical device, the electric current through this phase; evaluating, for at least one phase of the electrical device, the voltage of an electric arc between the electrical contacts that are associated with this phase; and calculating, for at least the phase of the electrical device, an energy value associated with the electric arc, by numerically integrating the product of the measured electric current and of the evaluated voltage, the integration being performed over a time interval starting from the detection of the movement of the electrical contacts.

A fluid-affected fuse includes a structural housing, a pair of electric terminals, one or more fuse elements, and a fluid arranged in an internal volume of the structure. The structure provides rigidity to the fuse. The terminals are coupled to the structural housing and are configured to be coupled to an electric power circuit of a battery circuit. The one or more fuse elements are electrically connected in series to the pair of electric terminals and are arranged in the internal volume. The fluid is configured to affect a temperature of the fuse element. A fluid-filled fuse is filled with fluid, optionally sealed, and operated with the increased heat capacity of the fluid to affect temperature of the fuse. A fluid-cooled fuse is filled with the fluid, undergoing a stream of the fluid thus allowing control of fuse temperature. A control system controls the fluid stream and fuse operation.

A fluid-affected fuse includes a structural housing, a pair of electric terminals, one or more fuse elements, and a fluid arranged in an internal volume of the structure. The structure provides rigidity to the fuse. The terminals are coupled to the structural housing and are configured to be coupled to an electric power circuit of a battery circuit. The one or more fuse elements are electrically connected in series to the pair of electric terminals and are arranged in the internal volume. The fluid is configured to affect a temperature of the fuse element. A fluid-filled fuse is filled with fluid, optionally sealed, and operated with the increased heat capacity of the fluid to affect temperature of the fuse. A fluid-cooled fuse is filled with the fluid, undergoing a stream of the fluid thus allowing control of fuse temperature. A control system controls the fluid stream and fuse operation.

A method for estimating a property of an electrical switching device includes: detecting a movement of electrical contacts of the switching device beyond an opening threshold; measuring, for at least one phase of the electrical device, the electric current through this phase; evaluating, for at least one phase of the electrical device, the voltage of an electric arc between the electrical contacts that are associated with this phase; and calculating, for at least the phase of the electrical device, an energy value associated with the electric arc, by numerically integrating the product of the measured electric current and of the evaluated voltage, the integration being performed over a time interval starting from the detection of the movement of the electrical contacts.

A method for operating a medium voltage circuit breaker or recloser comprising at least one electric pole, each including a movable contact and a fixed contact, being in a closed or an open position after switching operations of the medium voltage circuit breaker or recloser, and an electromagnetic actuator, includes: monitoring a travel curve of the movable contact, the travel curve being derived by an evaluation of a shape of an applied current and a shape of an applied voltage using a mathematical representation of the electromagnetic actuator.