Rated for motor switching — AC-23B duty cycle
The GS1DB4 is a fuse switch disconnector body from the TeSys GS range, designed for switching motor loads under AC-23B duty — the category that covers occasional switching of motors during normal operation, including starting, stopping, and inching. The rated operational current is 32 A at 400 V AC-23B, with a making capacity of 320 A and a breaking capacity of 256 A at the same voltage. That making-to-breaking ratio reflects the inrush current of an induction motor: the contacts must close into a stalled-rotor current several times the full-load rating, then interrupt the running current on a normal stop. For DC applications, the rating drops to 20 A at 440 V with two poles in series per phase (DC-23A and DC-23B). The rated operational power spans 15 kW at 400 V AC-23A/B up to 25 kW at 690 V AC-23A/B. The conventional free-air thermal current Ith is 32 A at 40 °C ambient, so the thermal path through the body and terminals is sized for continuous current at that level without exceeding the temperature rise limits of the housing.
Fault coordination with BS fuses
The short-circuit withstand rating is 80 kA at 400 V when protected by BS fuses, and the rated short-circuit making capacity Icm is 32 kA with the associated fuse rating. This means the disconnector body can survive a fault current up to 80 kA without rupturing, provided the upstream BS fuse clears the fault within its let-through energy limit. The fuse size is A1, BS type. In a panel build, the coordination study must confirm that the selected BS fuse's I²t curve falls below the disconnector's withstand curve at the available fault current — otherwise the body may sustain damage before the fuse opens. The rated insulation voltage Ui is 750 V AC, and the rated impulse withstand voltage Uimp is 8 kV. These figures define the clearance and creepage distances inside the body — adequate for 400 V line-to-line systems with a 8 kV impulse category, which covers most industrial distribution panels fed from a 400 V transformer secondary.
Mounting, wiring, and environmental limits
Mounting is plate or rail (DIN) — the body accepts either a backplate screw-down or a snap-on DIN rail footprint. The external operating handle can be mounted on the right side or frontally. Power-circuit terminals accept flexible cable from 6 to 25 mm² (0.009 to 0.04 in²) with screw terminals torqued to 3.2 N·m (28.3 lbf·in). The control-circuit terminals share the same torque spec. The ambient operating range is -20 to 70 °C, and the body carries IP20 protection with the terminal cover fitted. The housing material is rated for fire resistance at 960 °C per IEC 60695-2-1. The protective treatment is TH — tropicalized for humidity and fungus resistance. These specs suit the body for installation inside a panel with a minimum IP54 enclosure, not for direct washdown exposure.
Durability and lifecycle
Mechanical durability is rated at 10,000 cycles; electrical durability is 1,500 cycles under AC-23A or AC-23B, and 300 cycles under DC-23A or DC-23B. For a line-down spare, the AC-23A figure is the relevant one for normal motor switching — 1,500 cycles at full rated current is typical for a disconnector that sees occasional operation, not daily jogging. If the application requires frequent switching, a contactor ahead of the disconnector extends the service interval.