Abstract: A switch is disclosed, in particular a power switch, for low voltages. The switch includes mechanically separable contact elements, in abutment when the switch is closed and via which a current to be monitored flows through the switch, an electronic trigger unit, which triggers a respective contact mechanics unit if a current condition is satisfied. In the event of triggering, the contacts are separated and the switch is switched on via the contact mechanics unit. A supply unit is included to extract a first electric energy from the current flowing through the switch to supply the trigger unit with energy. To guarantee energy supply even when switching to a short-circuit, the contact mechanics unit is coupled to a conversion unit, which converts a portion of the mechanical energy to be provided during switching-on into a second electric energy that supplies the trigger unit with electric energy during switching-on.

Abstract: A current assignment method and a switch arrangement are disclosed for assigning current, the switch arrangement including two series-connected switches, each including a trigger unit to check whether a preset current condition is satisfied. A signal is sent by the trigger unit of a switch which is postpositionally placed when the current condition is satisfied, the signal at least preventing the immediate triggering of a correspondingly prepositionally placed switch after being received by the corresponding trigger unit. To achieve a technically simple communication connection between switches, in at least one embodiment each trigger unit is formed so as to send but and receive the signal, and each trigger unit includes a measurement unit for measuring an energy flow direction in a subordinate switch and a conversion unit for converting from sending to receiving or from receiving to sending appropriately when the energy flow direction is reversed.

Abstract: A zone selective interlocking device includes a first port, a second port, an input bus, an output bus and a query signal receiving branch. The first and second port each are switchable between two states, connected to the input bus and connected to the output bus, and the zone selective interlocking device is operable in a first mode. In the first mode, the query signal receiving branch is turned on. Within a preset timeslot, a link fault query signal is permitted to be inputted to the query signal receiving branch through the first port, while a link fault query signal is prevented from being inputted to the query signal receiving branch through the second port. Based on whether a link fault query signal is received within the timeslot, a judgment is made on whether a fault has occurred in a communication link connected to a corresponding port.

Abstract: A protection device, externally connectable to an existing circuit breaker with zone selective interlock functionality, enables a circuit breaker to implement directional zone selective interlock. The protection device includes a first input port and a first output port connectable to a circuit breaker, and second and third ports for connecting to a protection device of another circuit breaker and for transmitting interlock signals via an input bus and an output bus inside the EDP. A control unit is configured to enable one of the second and third ports as a second input port and the other as a second output port according to the direction of current currently flowing through the circuit breaker; and configured to forward an interlock signal from the first input port to the output bus and to forward an interlock signal on the input bus received from the second input port to the first output port.

Abstract: A method is disclosed for diagnosing faults on a communication bus used to transmit zone selective interlocking signals in a power distribution network. The method includes configuring interfaces of all protection devices connected to the same communication bus to be input ports within a first diagnosis time period; detecting, at each protection device connected to the communication bus, an input signal received by the input port thereof; and if abnormality is detected in the input signal, the protection device issuing a first alert associated with the corresponding interface.

Abstract: A switch is disclosed, in particular a power switch, for low voltages. The switch includes mechanically separable contact elements, in abutment when the switch is closed and via which a current to be monitored flows through the switch, an electronic trigger unit, which triggers a respective contact mechanics unit if a current condition is satisfied. In the event of triggering, the contacts are separated and the switch is switched on via the contact mechanics unit. A supply unit is included to extract a first electric energy from the current flowing through the switch to supply the trigger unit with energy. To guarantee energy supply even when switching to a short-circuit, the contact mechanics unit is coupled to a conversion unit, which converts a portion of the mechanical energy to be provided during switching-on into a second electric energy that supplies the trigger unit with electric energy during switching-on.

Abstract: A method is disclosed for diagnosing faults on a communication bus used to transmit zone selective interlocking signals in a power distribution network. The method includes configuring interfaces of all protection devices connected to the same communication bus to be input ports within a first diagnosis time period; detecting, at each protection device connected to the communication bus, an input signal received by the input port thereof; and if abnormality is detected in the input signal, the protection device issuing a first alert associated with the corresponding interface.

Abstract: A zone selective interlocking device includes a first port, a second port, an input bus, an output bus and a query signal receiving branch. The first and second port each are switchable between two states, connected to the input bus and connected to the output bus, and the zone selective interlocking device is operable in a first mode. In the first mode, the query signal receiving branch is turned on. Within a preset timeslot, a link fault query signal is permitted to be inputted to the query signal receiving branch through the first port, while a link fault query signal is prevented from being inputted to the query signal receiving branch through the second port. Based on whether a link fault query signal is received within the timeslot, a judgment is made on whether a fault has occurred in a communication link connected to a corresponding port.

Abstract: A protection device, externally connectable to an existing circuit breaker with zone selective interlock functionality, enables a circuit breaker to implement directional zone selective interlock. The protection device includes a first input port and a first output port connectable to a circuit breaker, and second and third ports for connecting to a protection device of another circuit breaker and for transmitting interlock signals via an input bus and an output bus inside the EDP. A control unit is configured to enable one of the second and third ports as a second input port and the other as a second output port according to the direction of current currently flowing through the circuit breaker; and configured to forward an interlock signal from the first input port to the output bus and to forward an interlock signal on the input bus received from the second input port to the first output port.

Abstract: A current assignment method and a switch arrangement are disclosed for assigning current, the switch arrangement including two series-connected switches, each including a trigger unit to check whether a preset current condition is satisfied. A signal is sent by the trigger unit of a switch which is postpositionally placed when the current condition is satisfied, the signal at least preventing the immediate triggering of a correspondingly prepositionally placed switch after being received by the corresponding trigger unit. To achieve a technically simple communication connection between switches, in at least one embodiment each trigger unit is formed so as to send but and receive the signal, and each trigger unit includes a measurement unit for measuring an energy flow direction in a subordinate switch and a conversion unit for converting from sending to receiving or from receiving to sending appropriately when the energy flow direction is reversed.