250 A AC-23B — what the ratings mean for the panel
The GS1NBR4 is a 4-pole fuse switch disconnector body from the TeSys GS range, rated 250 A in AC-23B duty at 400 V — that is the heavy switching category for motor loads and other high-inrush circuits, not just resistive heating. The same 250 A holds at 500 V and 690 V (with the terminal cover fitted), so the current rating does not derate across the common industrial voltage bands. Breaking capacity is 2000 A at 400 V AC-23B; making capacity is 2500 A at the same voltage. The short-circuit withstand rating of 80 kA tells you the body can survive a fault up to that level when protected by the correct BS fuses — the fuse does the interrupting, but the switch body must hold together through the let-through energy.
Sourcing and lifecycle — active, quoted to order
Sourced through independent distribution channels; availability and current pricing confirmed at RFQ against the BOM quantity.
Mounting and integration — rail or plate, 4-pole
Mounts on a rail or plate — the body accepts power circuit bars or screw terminals (95 to 240 mm² flexible). The 4-pole configuration (4P) means it switches all three phases plus neutral, common in distribution panels where the neutral must be switched with the phases. Dimensions are 12.2 in wide by 7.7 in high by 5.7 in deep — the width is the panel-space driver; the depth fits a standard 600 mm enclosure depth with room for cable bending behind the body.
Environmental and compliance — IP20, TH treatment, IEC standards
IP20 with the terminal cover fitted — finger-safe but not sealed against moisture; suitable for indoor panel installation. Protective treatment TH indicates tropicalised for humid environments. Operating temperature range is -20 to 70 °C, storage -40 to 80 °C. Compliant with IEC 60269-1, IEC 60269-2, and IEC 60947-3 — the fuse switch disconnector standard. Fire resistance is 960 °C on the body and 850 °C on the fuse cover per IEC 60695-2-1.