Current transformer having a short-circuit device

The invention relates to a current transformer (1) having connection contacts (2) for contacting a secondary winding, said current transformer having a short-circuit device (3', 3'') for shorting the connection contacts (2), wherein the short-circuit device (3', 3'') has a mechanically movable conductor (4), which can be brought into a circuit between the connection contacts (2) of the secondary winding. The short-circuit device (3', 3'') is integrated in a housing (14) that encloses the current transformer (1), and the movable conductor (4) is brought into the circuit between the connection contacts (2) by means of a rotational or pivoting motion such that the circuit of the secondary winding is shorted.