Switch disconnector for DC PV and marine duty
The C634320D3S is a ComPacT NSX DC EP switch disconnector, 4-pole fixed-mount, rated 320 A at 1500 V DC in both DC-22A and DC-PV2 utilization categories. That means it handles the high-voltage DC side of a photovoltaic combiner box or the main DC bus on a marine vessel — the 1500 V DC operational voltage and 1600 V DC rated insulation voltage give it the clearance for ungrounded arrays and shipboard battery banks.
Short-time withstand (Icw) is 7.56 kA for 1 s, and the switch-disconnector alone makes 7.56 kA peak (Icm). The 8 kV impulse withstand (Uimp) gives it the surge margin for lightning-induced transients on exposed rooftop arrays. Mechanical durability is 8000 cycles; electrical durability is 3000 cycles at full rated current and voltage. That is typical for a switch-disconnector — it is a disconnecting means, not a daily-operating contactor. For PV isolation or marine battery disconnect, the cycle life is more than sufficient.
Fixed backplate mount, 185 mm wide × 255 mm high × 110 mm deep. Front connections on both sides — busbar or cable entry from above and below. The 45 mm connection pitch matches standard DC busbar systems. No visible break (the toggle does not show the contact gap), so verify isolation with a meter before working downstream.