A coil assembly for a magnetic actuator is described, the coil assembly comprising: —a tubular coil holder (100) comprising a first (110) and second open distal end (120); —the first open distal end comprising an outer circular rim (112) and an inner circular rim (114) separated by a circular groove (116); —the second open distal end comprising an outer circular rim (122); the tubular coil holder further comprising a central circular rim (130) arranged substantially halfway between the inner circular rim of the first open distal end and the outer circular rim of the second open distal end; —a coil (140) formed of a single wire (150) the coil comprising a first coil section (142) arranged in a first winding area (144) between the inner circular rim of the first open distal end and the central circular rim, and a second coil section (146) in a second winding area (148) between the central circular rim and the outer circular rim of the second distal end; the first coil section and the second coil section being wound about the tubular coil holder in opposite directions; whereby a first end (152) and a second end (154) of the single wire are arranged in the circular groove, the inner circular rim comprising a longitudinal groove (114.1) to extend the first aid and the second end of the single wire from the circular groove to the first winding area; the central circular rim composing a longindinal groove (130.1) to extend the single wire form the first winding area to the second winding area and vice versa; —an external connection (160) comprising a first conductor (162) and a second conductor (164); whereby an end of the first conductor is electrically connected to the first end of the single wire so as to form a first electrical connection (166) arranged in the circular groove and an end of the second conductor is electrically connected to the second end of the single wire so as to form a second electrical connection (168) in the circular groove and wherein the first and second conductor extend through the outer circular rim via a longitudinal groove (112.1) of the outer circular rim.