The GS1K3 is a TeSys GS fuse switch disconnector body — a 3-pole unit that accepts NFC-type fuses in the 22 x 58 mm size. It's the switching and isolating element in a fused disconnect assembly, rated to make and break circuits under load per IEC 60947-3. Rated operational current hits 125 A at 400 V AC-23A and AC-23B, with a breaking capacity of 1000 A at 400 V under the same duty. That AC-23B rating means it's certified for occasional switching of motor loads — not just isolation — so it handles the inrush and breaking arc of inductive circuits.
Power connections accept bars or screw terminals for 35 to 95 mm² flexible cable, torqued to 12 N·m. The operating handle can be mounted externally on the front or right side, which gives panel layout flexibility when the disconnect needs to sit behind a door or next to a busway. IP20 with the terminal cover fitted — finger-safe but not washdown-rated.
If you're replacing this in a panel, you'll need to evaluate the current TeSys GS catalog for a functional equivalent — same fuse size (22 x 58 mm), same NFC fuse type, same 125 A rating at 400 V AC-23B — and verify the mounting footprint and handle position match your enclosure cutout.
Making capacity: 1250 A at 400 V AC-23B. Short-circuit making capacity with gG (gI) fuse protection: 100 kA at 400 V, with the associated fuses rated 125 kA. Insulation voltage: 750 V AC. Impulse withstand: 8 kV. Mechanical durability: 10,000 cycles; electrical durability: 1,000 cycles under AC-23A or AC-23B. Fire resistance: the fuse cover withstands 850 °C, the body 960 °C, both per IEC 60695-2-1. Protective treatment is TH (tropicalized). Standards compliance includes IEC 60947-3, IEC 60269-1, and IEC 60269-2.