The invention relates to a disconnector device (3) for disconnecting an electrical circuit, wherein the electrical circuit is switched by a contactor (2) between an open position and a closed position, the disconnector device (3) using the contactor (2) for disconnecting the electric circuit. The disconnector device (3) comprises means (7, 8; 9, 10) for locking the contactor (2) in the open position, in which open position contacts of the contactor (2) are in a first position disconnecting the electrical circuit. An arrangement (1) comprising the disconnector device (3) and a contactor (2) is also provided.