Electrical apparatus for the short-circuit protection of a three-phase load in a three-phase system

摘要

An apparatus for short-circuit protection of a three-phase load in a three-phase system includes an input for connection of the apparatus to a three-phase network, an output for connection of the three-phase load to the apparatus, a means for producing an auxiliary short circuit in the three-phase network by ignition of the means, a means for identifying a short circuit at the three-phase load, and a means for generating an ignition pulse upon identification of the short circuit. The means for producing the auxiliary short circuit and the means for identifying the short circuit are provided in the current path between the input and the output. The means for producing the auxiliary short circuit is ignitable by the ignition pulse. The means for generating the ignition pulse is formed so that the ignition pulse can be generated by a short-circuit current established by the means for identifying the short circuit.

主权项

1. An apparatus for the short-circuit protection of a three-phase load in a three-phase system, said apparatus comprising:
an input for connection of the apparatus to a three-phase network; an output for connection of the three-phase load to the apparatus; a means for producing an auxiliary short circuit in the three-phase network by ignition of the means; a means for identifying a short circuit at the three-phase load, wherein the means for identifying the short circuit comprises a current sensor and a means for identifying a switching threshold comprised of a galvanic isolation device; and a means for generating an ignition pulse upon identification of the short circuit,
wherein the means for producing the auxiliary short circuit and the means for identifying the short circuit are provided in the current path between the input and the output,wherein the means for producing the auxiliary short circuit is ignitable by the ignition pulse,wherein the current sensor is arranged in the current path of a phase of the three-phase network,wherein the means for identifying the switching threshold cooperates with the current sensor, andwherein the means for identifying the switching threshold signals the identification of a short circuit to the means for generating the ignition pulse if a predefined switching threshold is exceeded.