Abstract: A switch lock for an electrical switching device, e.g. a circuit breaker, motor circuit breaker, or isolating switch, which is an improved switch lock, that can be made with fewer parts and at lower cost. Furthermore, an electrical switching device can contain this switch lock. Due to an appropriate arrangement of the spring coupling points and an appropriate spring dimensioning, as well as an appropriate geometric design of the contact piece holder, this switch lock can do without separate lock and contact pressure springs, insofar as their functions are combined in one spring.

Abstract: An electronic overcurrent release for circuit breakers includes a first setting device connected to at least one control input of a microcontroller and configured to set a selected suitable nominal current value in a range between a minimum nominal current value and a maximum nominal current value. A second setting device is connected to at least one control input of the microcontroller and configured to set a selected suitable lag level, the second setting device having a test position. In the test position, the microcontroller has a set fixed test current value, which is less than the minimum nominal current value, and a set fixed test delay time, the microcontroller providing a release signal at a release signal output upon at least one of the phase currents exceeding a value of the set fixed test current value and a time of the set fixed test delay time.