Abstract: A power distribution protection system and method uses communications to coordinate operation of fault protection devices. Communications may be prioritized wherein messages of a lower priority are held or discarded in favor of messages of a higher priority, for example, messages indicating a fault condition. The devices may use multiple channel access schemes in accordance with a priority of a message to be communicated.

Abstract: A power distribution protection system and method uses communications to coordinate operation of fault protection devices. Communications may be prioritized wherein messages of a lower priority are held or discarded in favor of messages of a higher priority, for example, messages indicating a fault condition. The devices may use multiple channel access schemes in accordance with a priority of a message to be communicated.

Abstract: A power distribution protection system and method uses communications to coordinate operation of fault protection devices. Communications may be prioritized wherein messages of a lower priority are held or discarded in favor of messages of a higher priority, for example, messages indicating a fault condition. The devices may use multiple channel access schemes in accordance with a priority of a message to be communicated.

Abstract: System and equipment protection is provided for an electrical power distribution system via one or more protection arrangements for detecting and responding to faults in electrical power distribution systems. The one or more protection arrangements detect whether faults are external or internal to a distribution equipment configuration in a power system via directional sensing. The protection arrangements also detect and respond to faults in a power distribution system utilizing various combinations of primary and back-up protection arrangements that are operational simultaneously and in both closed-loop and open-loop configurations.

Abstract: System and equipment protection is provided for an electrical power distribution system via one or more protection arrangements for detecting and responding to faults in electrical power distribution systems. The one or more protection arrangements detect whether faults are external or internal to a distribution equipment configuration in a power system via directional sensing. The protection arrangements also detect and respond to faults in a power distribution system utilizing various combinations of primary and back-up protection arrangements that are operational simultaneously and in both closed-loop and open-loop configurations.

Abstract: A control circuit and method are provided for a circuit interrupter that predicts the occurrence of fault-current zero crossings. This prediction is utilized to control the operation of a circuit interrupter at a desirable point in the periodic wave form of the fault current. For example, the control circuit is useful to control a synchronous interrupter by accurately generating a trip signal to the synchronous interrupter for operation in the vicinity of the zero crossing of the current wave form. In a preferred arrangement, the control circuit utilizes the quotient of a sensed current signal and the time rate of change of the sensed current signal. In one specific arrangement for circuit environments that might include conditions that could lead to false results, the time rate of change of the quotient is utilized to provide a control signal.

Abstract: A switchgear module is provided that is assembled from one or more molded housing portions to provide a gas-tight volume for the housing of electrical components. The switchgear modules include provisions for assembly of various combinations of switchgear modules into a variety of electrical circuit configurations while maintaining a gas seal of the switchgear modules. In a preferred arrangement, the switchgear module includes bus conductors that are integrally incorporated during the molding of the switchgear module housing and that are accessible from opposite sides of the module. Further, the switchgear module includes integrally molded features for providing access to make electrical interconnections between the bus conductors of adjacently positioned switchgear modules.

Abstract: A loadbreak switch is provided that utilizes a pivotally mounted movable jaw contact and a main stationary contact that is positioned in the middle of an arc runner. For operation at voltages 15 kV and above, the switch utilizes a shunt contact that bridges the arc runner and that is above and coplanar with the main stationary contact. A magnetic field is developed by the current that flows through a coil of wire disposed around the arc runner. This configuration when utilized in an environment of insulating gas, provides efficient extinguishing of arcs upon opening of the contacts. Further, the open jaw contact is easily visible to establish an open gap.