Panel fit and mounting constraints
The GS1TB3 body measures 16.6 in (421.5 mm) wide by 12.6 in (320 mm) tall by 10.6 in (268 mm) deep — the width is the dimension that governs enclosure door cutout and sidewall clearance when mounted on a plate or rail. Mounting support is plate or rail; the body itself carries IP20 protection with the terminal cover fitted, so the enclosure must provide the environmental seal for the application.
Rated current, power, and duty-cycle limits
Rated operational current is 800 A at 400 V in AC-23A and AC-23B duty, derating to 630 A at 500 V and 690 V in the same categories — the 800 A figure applies only at 400 V, so a 480 V or 600 V line drops the usable current to 630 A. Rated operational power reaches 450 kW at 400 V and 500 V AC-23A/B, climbing to 600 kW at 690 V AC-23A/B and 750 kW at 690 V AC-23A/B — the higher power at 690 V reflects the same 630 A current limit at that voltage level. Conventional free-air thermal current is 800 A at 104 °F (40 °C), matching the 400 V AC-23A rating — the thermal current is the ceiling for continuous duty in open air, not inside a sealed enclosure.
Fault-breaking capacity and fuse coordination
Breaking capacity is 6400 A at 400 V AC-23B; making capacity is 8000 A at the same voltage — these are the switch body's own ratings without upstream protection. With BS-type fuses fitted (sizes C3, C1, C2), the rated short-circuit making capacity jumps to 800 kA at 400 V — the fuse limits the let-through energy, not the switch itself. Rated impulse withstand voltage is 12 kV, and insulation voltage is 1000 V AC — the switch is designed for 600 V class systems with margin for transient overvoltages.
Lifecycle status and sourcing reality
No official successor order code is recorded on this listing; the part is available through independent surplus and broker channels, sourced to order against an RFQ with availability and pricing confirmed at quote time. The TeSys GS range (GS1T family) includes other fuse switch disconnector bodies with different current ratings and fuse types — a functional replacement would require matching the pole count, BS fuse accommodation, and panel cutout dimensions.
Termination, torque, and environmental ratings
Power circuit connections accept bars or screw terminals up to 2 × 0.5 in² (300 mm²) flexible or 2 × 0.3 in² (185 mm²) flexible; tightening torque for both power and control circuit bars is 389.4 lbf·in (44 N·m). Operating temperature range is -4 to 158 °F (-20 to 70 °C); the body carries protective treatment TH for tropicalized environments. Fire resistance is 1760 °F (960 °C) for the body and 1562 °F (850 °C) for the fuse cover per IEC 60695-2-1 — relevant for installations requiring glow-wire testing. Mechanical durability is 8000 cycles; electrical durability is 500 cycles in AC-23A/B and 100 cycles in DC-23A/B — the switch is designed for infrequent manual operation, not high-cycle automation.