The Schneider Electric TA10D4S0404TPE is an automatic transfer switch (ATS) from the TransferPacT series, built to IEC 60947-6-1. It automatically or manually switches a load between two sources of supply — typically utility and generator — with a rotary knob selector and mechanical interlocking that prevents both sources closing simultaneously. Rated 40 A at 400 V AC, 50/60 Hz, with 4 poles (4P). The utilization category is AC-33B, which covers mixed resistive and motor loads plus high inrush — the standard duty for building emergency-power transfer switches. The switch is rated for uninterrupted duty, meaning it can carry the load continuously without derating.
The AC-33B rating at 40 A means this switch handles the combined load of lighting, heating, and small motors typical in commercial and light industrial emergency circuits. The conventional free-air thermal current (Ith) is also 40 A at 60 °C, so no additional derating is needed at that ambient — a clean match for a 40 A feeder. Short-circuit performance: rated short-time withstand current (Icw) is 5 kA for 0.1 s, and the short-circuit making capacity (Icm) is 15 kA at 400 V AC for the switch-disconnector alone, rising to 75 kA with an upstream circuit breaker. This tells you the switch can close onto a fault and survive, but the upstream protection must be coordinated to keep let-through energy within the switch's limits. Mechanical durability is 8000 cycles — typical for a transfer switch in standby service where it cycles only during weekly tests and actual outages. Not a high-cycle part for frequent switching; it's built for reliability over decades of occasional operation. The front face carries IP40 in auto mode (protection from tools and small wires), while the inside of the enclosure is IP20 (finger-safe).
The 310 mm width and 147 mm height mean it occupies a full-width slot in a standard 600 mm enclosure. Screwed connections on both the upside (source) and downside (load) sides — expect to torque per Schneider's published values. Depth is 94 mm, so it clears a 120 mm deep enclosure back wall with room for wiring. The padlockable OFF position and contact position indicator (3 positions: source 1, OFF, source 2) are standard for lockout/tagout compliance. Signal contacts are configurable: 1 NO + 2 NC, or 1 NC + 2 NO, or 2 NO — allows remote status monitoring of source availability and switch position.