A magnetic chamber is disclosed for electromagnetic low voltage switchgear, especially a compact reversing starter, including two magnetic drives which are each actuated by a main slide. The magnetic chamber is designed, in at least one embodiment, to receive both magnetic drives of the electromagnetic low voltage switchgear, and a mechanical reversing locking device held in a mobile manner for the alternating mechanical locking of the two magnetic drives is arranged in the magnetic chamber, the mechanical locking device acting on the two main slides. An electromagnetic low voltage switchgear is disclosed, especially a compact reversing starter, including two magnetic drives which are each actuated by a main slide, both magnetic drives being arranged in a magnetic chamber. The mechanical reversing locking device held in a mobile manner, in at least one embodiment, engages with the main slide of one of the magnetic drives, according to the position of the locking device, in order to fix said magnetic drive.