The Schneider A9GSB350 is a 3-pole fuse-disconnector from the Acti9 SBI series, rated for 50 A at 690 V AC. It accepts 14 x 51 mm fuse links with a GG or AM curve, making it a straightforward line-side disconnect or branch-circuit protector in a 3-phase panel.
The 50 A rated current (In) is the continuous thermal rating at 690 V AC — sized for a 3-phase motor load around 37 kW or a resistive load bank at that current. The 14 x 51 mm fuse size is a standard NH-style cylindrical fuse; the GG (general-purpose) or AM (motor-protection) curve lets you match the fuse to the load type. GG covers cable and general protection; AM handles motor starting inrush without nuisance blowing.
The 79.5 mm width (9 x 9 mm pitches) takes up 9 module spaces in a standard enclosure — plan your DIN rail layout accordingly. Screw-clamp terminals accept 1 to 16 mm² rigid or 1 to 10 mm² flexible cable; strip length is 10 mm. Tightening torque is 2.2 N.m on both top and bottom connections.