Abstract: A trip device is for an electrical power breaker, for tripping on a short-circuit. It is embodied as an analogue electrical circuit. The circuit components and devices necessary for tripping on a short circuit form a discrete module, completely independent of other trip devices on the power breaker. A direct current is provided by transformers together with rectifiers which flows through a power semiconductor switched to conduct in the normal operating state of the power breaker. A measurement and control circuit is controlled by way of a voltage generated across a measuring resistance through which the direct current flows and closes the power semiconductor when a threshold value is exceeded. The current is then commutated from the power semiconductor to the trip magnet which opens the switch contacts with a particularly small delay.