A lockable manually-operated rotary actuator for an electrical switching device includes a turning handle mounted on a housing and connected to an operating axle of the switching device. A pivotably or displaceably mounted locking member in or on the turning handle is configured to lock the turning handle in a locking position via an operative connection with the housing. At least one released locking opening is present in the locked position with at least one padlock. A protective cap is disposed over the turning handle and provides access to the at least one released locking opening, a shape of the protective cap being such that the protective cap conforms to a shape of the turning handle and is fixed to the housing via a positive connection.