800 A fuse switch disconnector for motor branch circuits
The GS1TBR3 is a TeSys GT fuse switch disconnector body — not a contactor, but the disconnect and fuse-holder for the motor branch circuit. It carries 800 A continuous at 400 V in AC-23B duty, which is the heavy motor-start category (switching motors and other highly inductive loads). Rated operational power reaches 450 kW at 400 V AC-23A/B and 750 kW at 690 V AC-23A/B — this is a high-power disconnect for large motor starters or distribution switchboards, not a panelboard feeder.
Making capacity is 8000 A at 400 V AC-23B; breaking capacity is 6400 A at the same voltage. These are the fault-closing and fault-opening ratings — the switch must close onto a short-circuit without welding and open a fault without external arc. The 12 kV rated impulse withstand voltage (Uimp) confirms the insulation system handles lightning or switching surges on a 1000 V insulation-rated system. Short-circuit making capacity (Icm) is 800 kA at 400 V — but this is conditional on the associated BS fuse clearing the fault. The switch body itself is not a stand-alone interrupting device; it relies on the BS fuses (sizes C1, C2, C3) for the actual interruption. The fuse cover passes a 960 °C glow-wire test; the body passes 850 °C per IEC 60695-2-1.
Physical fit and mounting — panel layout constraints
Mounts on a plate or rail. The body dimensions are 10.2 in deep by 16.6 in wide by 10.6 in high — this is a large disconnect, not a DIN-rail component. The power circuit terminals accept bars up to 63 mm² (two bars) or 60 mm² (five bars), with a tightening torque of 44 N.m. Plan for generous gland-plate space and bus-bar bending radius around this footprint. IP20 with terminal cover per IEC 60529 — finger-safe but not sealed against dust or moisture. The TH protective treatment (tropicalization) means the internal surfaces resist humidity and fungal growth, which matters for unheated electrical rooms or outdoor enclosures.
Lifecycle and sourcing — active, quoted to order
Mechanical durability is 6000 cycles; electrical durability ranges from 100 cycles in DC-23A/B to 500 cycles in AC-23A/B. These are not high-cycle switching devices — they are intended for infrequent disconnect and isolation, not daily motor starting.