Frequency converter having a power end stage, which is configured to drive a synchronous motor that is connected or able to be connected to an output side of the power end stage, wherein an intermediate circuit capacitor is connected to an input side of the power end stage, wherein - a thyristor is formed as an electronic switching element, by way of which the input side of the power end stage is able to be short-circuited, - an actuation circuit of the electronic switching element is formed, which actuation circuit is configured so as to be able to be transferred between a non-activated state and an activated state, - the actuation circuit is configured to be transferred to the activated state when the voltage applied to the input side by the intermediate circuit capacitor has dropped to or below a first threshold value, - the actuation circuit is configured to trigger the short circuit of the electronic switching element in the activated state of the actuation circuit by way of a voltage that is applied from the output side of the power end stage to the input side thereof during generator operation and exceeds a second threshold value, - the electronic switching element has a switching input, by way of which it is able to be operated, - the actuation circuit is configured in the non-activated state to switch the switching input to a potential of zero by way of a deactivation element (16, 23), - the actuation circuit has at least one circuit breaker by way of which the intermediate circuit capacitor is able to be disconnected from the input side, - the deactivation element (16, 23) and the circuit breaker are configured to switch in a coupled manner and the switching input of the electronic switching element is configured in the activated state to be connected to the input side by means of a voltage divider and to be operated by way of electrical energy from the generator operation, - the electronic switching element is configured to be in an open position in the non-activated state of the actuation circuit, - and the actuation circuit is furthermore configured to compulsorily raise the circuit of the switching input to a potential of zero when the intermediate circuit capacitor is disconnected from the input side and to disconnect the switching input of the electronic switching element in the non-activated state from a voltage applied to the input side. - a thyristor is formed as an electronic switching element, by way of which the input side of the power end stage is able to be short-circuited, - an actuation circuit of the electronic switching element is formed, which actuation circuit is configured so as to be able to be transferred between a non-activated state and an activated state, - the actuation circuit is configured to be transferred to the activated state when the voltage applied to the input side by the intermediate circuit capacitor has dropped to or below a first threshold value, - the actuation circuit is configured to trigger the short circuit of the electronic switching element in the activated state of the actuation circuit by way of a voltage that is applied from the output side of the power end stage to the input side thereof during generator operation and exceeds a second threshold value, - the electronic switching element has a switching input, by way of which it is able to be operated, - the actuation circuit is configured in the non-activated state to switch the switching input to a potential of zero by way of a deactivation element (16, 23), - the actuation circuit has at least one circuit breaker by way of which the intermediate circuit capacitor is able to be disconnected from the input side, - the deactivation element (16, 23) and the circuit breaker are configured to switch in a coupled manner and the switching input of the electronic switching element is configured in the activated state to be connected to the input side by means of a voltage divider and to be operated by way of electrical energy from the generator operation, - the electronic switching element is configured to be in an open position in the non-activated state of the actuation circuit, - and the actuation circuit is furthermore configured to compulsorily raise the circuit of the switching input to a potential of zero when the intermediate circuit capacitor is disconnected from the input side and to disconnect the switching input of the electronic switching element in the non-activated state from a voltage applied to the input side.