Operating Shafts A range of operating shafts in various lengths for use with the ABB OS range of switch disconnectors. Used where a greater depth of mounting the 'Fuse Switch Disconnector' is required and the supplied shaft is insufficient Shafts can be reduced in length to suit specific requirements The operating shaft is available in various lengths ABB OS Range A fused switch disconnector provides a cost effective means of short circuit protection, together with circuit isolation. The choice of fuse rating determines the level of protection, the maximum value is determined by the fused switch disconnector. These items have been tested in accordance with EN 60947-3.