The GS1VD3 is a TeSys GS fuse switch disconnector body — three poles, DIN-rail mount, rated for a conventional free air thermal current of 1250 A at 40 °C. It's the core switching element for a fused disconnect assembly, meaning the fuse size (T4 DIN type) and the switch body are matched as a set. The 1000 A rated operational current at 400 V AC-23A tells you it handles motor switching duty (AC-23A covers occasional switching of motors with high inrush) at that full ampacity, not just resistive loads.
Rated insulation voltage is 1000 V AC, and impulse withstand is 12 kV — that covers 690 V line-to-line systems with margin for switching surges. Short-circuit making capacity (Icm) is 100 kA at 400 V when protected by gG fuses rated 1250 A; that's the peak let-through the switch must survive, and it's the number the panel SCCR study uses. Electrical durability is 500 cycles for AC-23A/B and 100 cycles for DC-23A/B — this is a disconnect, not a contactor for frequent cycling, so those numbers are typical for infrequent manual switching. Mechanical durability is 5000 cycles, which is the handle life before the mechanism wears.
Power circuit connections accept bars or screw terminals up to 185 mm² flexible — that's a heavy cable, consistent with the 1250 A rating. Tightening torque is 44 N·m for both bar and screw connections, so a torque wrench is required on install. Protective treatment is TH (tropicalized, heat and humidity resistant), which matters if the panel sits in a non-conditioned space.
Designed to IEC 60269-1, IEC 60269-2, and IEC 60947-3. The IEC 60269 series covers fuse specifications (part 1 general, part 2 for fuse-links); IEC 60947-3 covers disconnectors and switch-disconnectors. Fire resistance is tested to IEC 60695-2-1: the fuse cover withstands 850 °C, the body 960 °C. No UL or CSA listing is stated in the spec record, so for North American jobs verify acceptance with the local code authority.