Abstract: A method of operating a protection device arranged between an electrical three-phase power source and at least one electric motor, the method including for each phase of the power source, acquiring over time a corresponding phase current flowing from the power source to the at least one electric motor; based on the acquired phase currents, detecting in which current stage each electric motor is, among an initial stage, an intermediate stage successive to the initial stage and a steady-state stage successive to the intermediate stage; calculating an active threshold value depending on the detected stage of each electric motor, the active threshold value during the intermediate stage following a predetermined decreasing function over time.

Abstract: In one aspect, the present invention provides an electromagnetic circuit interrupter for use in a high voltage direct current (DC) aircraft power distribution system. The electromagnetic circuit interrupter comprises a contact mechanism operable to separate first and second electrical contacts by a first predetermined distance d1 for a predetermined time ? so as to sustain an arc when the contact mechanism is opened. The contact mechanism is further operable to separate the first and second electrical contacts by a second predetermined distance d2 after the predetermined time ? so as to extinguish the arc. The first predetermined distance d1 is less than said second predetermined distance d2. By deliberately sustaining the arc for a relatively long period of time, this aspect of the present invention is particularly useful for extending the operational lifetime of the contacts and thereby of the electromagnetic circuit interrupter itself.

Abstract: A magnetic circuit includes a stationary iron core, a permanent magnet, and an armature, in a circular pattern. A contact mechanism spring separates the armature from the stationary iron core to open the magnetic circuit to switch a contact mechanism to a reset position. A coil on the magnetic circuit generates a magnetic flux in a direction same as that of the permanent magnet when an overload is detected and in an opposite direction when a predetermined time is elapsed after detecting the overload. A reset bar switches a movable stopper between an engaging position and a non-engaging position with the contact mechanism against a biasing force of the contact mechanism spring.

Abstract: A solenoid assembly for a circuit breaker having a clapper with an increased mass is provided. The mass, preferably at least one non-ferrous slug, increases the mass of the clapper so that the solenoid response time is slowed. That is, the added mass creates an inertial delay that slows the solenoid clapper as the clapper moves between the first position and the second position. Preferably, the delay is between 48 ms and 60 ms, and more preferably 50 ms. The clapper having a non-ferrous slug may also be incorporated into existing circuit breakers by, for example, coupling the non-ferrous slug to the preexisting clapper, or replacing the clapper with a clapper assembly having at least one non-ferrous slug thereon.

Abstract: A fault interrupter and a method of operating a fault interrupter to reduce arcing time during fault interruption. Fault interrupter operation is delayed following detecting a peak current such that its operation occurs at a point of the current wave resulting in reduced arcing during fault isolation.

Abstract: A fast engage, slow release electrical actuator combines an electromagnetic actuator with a thermal actuator, the latter which retains the electromagnetic actuator after the former has been actuated to delay the release thereof.

Abstract: A control valve used in a variable displacement compressor. A valve chamber port communicates with a valve chamber. A port is connected with the valve chamber by a valve hole. A valve body selectively opens and closes the valve hole for controlling flow of fluid between the ports. An actuator actuates the valve body. A coil bobbin is accommodated in the casing. A coil is wound about the bobbin. The bobbin contacts a first connector plate. A ground lead of the coil is connected to the first connector plate. A terminal is connected to a supply lead of the coil. A second connector plate is attached to a lid. The second connector plate faces the first connector plate. Flexible contacts are located between the first connector plate and the second connector plate to electrically connect the connector plates.

Abstract: An electrical contact position indicator assembly is operatively coupled to an electrical device, such as a recloser, for indicating the relative position of the contacts of the electrical device, i.e., opened or closed, at any given time during operation of the electrical device. The position indicator assembly includes a movable indicator having first indicia to indicate that the contacts are opened, and second indicia to indicate that the contacts are closed. Each of the first and second indicia of the indicator lies in more than one plane. Preferably, each of the first and second indicia of the indicator lies on a three-dimensional, curvilinear or spherical surface. In the preferred embodiment, the indicator includes a mechanical linkage to the contact opening and closing assembly.