Abstract:
A knife switch (100; 130) comprising a hinged contact knife (103), moveable between at least two positions, and a first electric contact element (105), said contact knife being electrically connectable at a first end (104) to a first electric conductor (109), and further comprising an operator device (111) for moving said contact knife between the at least two positions, of which a first position is an open position in which a second free end (106) of the contact knife is disconnected from any electrical contact, and a second position is a first contact position in which the second free end (106) of the contact knife is in electrical contact with the first electric contact element (105). The second free end (106) of the contact knife is provided with a dynamic electric field control device (116) comprising an electrically conductive element. A switching device (200) for electric power distribution switchgear, comprising a two-position switch (205) comprising an at least partly electrically conductive housing (203), a three-position switch (130) comprising the knife switch (130) for connecting the two-position switch (205) to a first electric conductor (109), wherein the at least partially electrically conductive housing (203) is connected to a second electric conductor (235). A switchgear comprising switching devices.