The GS1F3 is a TeSys GS fuse switch disconnector body — a 3-pole, NFC-type unit that accepts 14 x 51 mm fuse links. It is the switching and isolation point for a fused circuit, not the fuse itself; you pair it with the appropriate gG or aM fuse links for overcurrent and short-circuit protection. Rated 50 A in AC-23B duty at 400 V, meaning it handles motor switching loads (frequent on/off under load) up to that current. The same 50 A rating holds at 500 V and 690 V AC-23B, so the current capability does not derate with higher voltages in this duty class — unusual and worth noting for a 690 V panel. Breaking capacity is 400 A at 400 V AC-23B; making capacity is 500 A at the same condition.
Mounts on a rail or plate — the evidence lists both options, so it is not limited to DIN-rail only; a backplate screw-down is possible. Terminals accept 6 to 25 mm² flexible copper on screw terminals, torqued to 3.2 N·m. IP20 with the terminal cover fitted, which is standard for inside-enclosure use where no washdown or dust ingress is expected. The operating handle can be mounted on the external right side or externally on the front, giving some flexibility for enclosure layout — useful when the switch sits deep in a cabinet and the handle needs to protrude through the door.
The 14 x 51 mm fuse size and NFC type are common in European-origin panels; verify the fuse-link rating (gG or aM) separately since the disconnector body itself does not set the overcurrent threshold — that is the fuse's job.
Listed to IEC 60947-3 (switch-disconnectors), IEC 60269-2 (fuse requirements), and IEC 60269-1 (general fuse standards). Fire resistance is tested to 850 °C on the fuse cover and 960 °C on the body per IEC 60695-2-1. The rated impulse withstand voltage is 8 kV, and the insulation voltage is 750 V AC.