DC PV switch disconnector for photovoltaic arrays
The Schneider Electric C634500D1S is a ComPacT NSX500NA DC PV switch disconnector, a 4-pole fixed-mount unit rated for 500 A at 1000 V DC. It is designed for photovoltaic (PV) applications where a visible-break isolation point is required on the DC side of the array, though this unit does not itself provide a visible break — the contact position indicator on the toggle tells you the state without needing to open the enclosure. The DC-22A utilisation category means it is rated for switching DC loads with moderate overloads — typical for PV combiner boxes and inverter DC disconnects where the load is mostly resistive but includes some inrush from filter capacitors. The 500 A rating at 1000 V DC covers the main string current of a large commercial or utility-scale PV installation. The 1000 V DC insulation rating matches the typical maximum system voltage for modern PV modules.
The rated short-time withstand current (Icw) is 6 kA for 1 second, and the rated short-circuit making capacity (Icm) is also 6 kA for the switch-disconnector alone. The 8 kV rated impulse withstand voltage (Uimp) covers transient overvoltages from lightning or switching surges on the DC bus. The IP40 rating keeps out tools and wires larger than 1 mm, but it is not sealed against water; plan for a weatherproof enclosure if the switch is mounted outdoors. The conventional free-air thermal current (Ith) is 400 A at 65 °C, which is lower than the 500 A DC-22A rating. This means the 500 A rating depends on the DC-22A switching duty — for continuous current-carrying in free air at elevated ambient, the limit is 400 A. If your PV string current is a steady 500 A in a hot enclosure, you need to check the thermal derating for your specific ambient. Mechanical durability is 5000 cycles; electrical durability is 1000 cycles at rated voltage and current. This is not a daily-operating switch — it is a disconnect for infrequent isolation during maintenance or emergency shutdown. If your design requires frequent switching under load, look at a contactor or circuit breaker instead.
The switch is fixed-mount on a backplate, not DIN-rail. The 185 mm width, 255 mm height, and 110 mm depth mean it needs a cutout or mounting footprint on the panel backplate. The connection pitch is 45 mm, and both upside and downside connections are front-accessible, so busbars or cables land on the front terminals — no rear-access required. The toggle control gives a positive mechanical indication of contact position. The IK07 impact rating means the switch body can withstand a 2 J impact — enough for accidental tool drops in a cabinet, but not for direct blows in an unenclosed location.