The TA16D3L1254TPE is a 125 A automatic transfer switch from the TransferPacT range, built to IEC 60947-6-1. That standard covers transfer switches for emergency or standby power — it's the spec that governs the whole class. The AC-33B utilization category means it's rated for mixed motor and resistive loads, typical in pump, fan, and compressor changeover applications. 125 A at 400 V AC puts it in the sweet spot for a 60–80 kVA generator feed or a main breaker downstream of a 125 A MCCB. Short-time withstand (Icw) is 10 kA for 0.1 s, and making capacity (Icm) hits 154 kA with an upstream circuit breaker. That tells you it can close onto a fault and survive, provided the upstream protection is coordinated. Without an upstream breaker, the switch alone makes 20 kA at 400 V. The front face carries IP40 (tools and small wires stay out), but inside the enclosure it's IP20 — finger-safe only. Connection pitch is 30 mm, so standard busbar or cable lugs fit. The 3-position contact indicator (I-O-II) plus padlock hasp in OFF give a visible isolation break — the switch is marked as suitable for isolation, which is a requirement for many site safety procedures.
Deployment context
This is a fixed-mount automatic transfer switch (ATS) for changeover between two sources of supply — typically mains and generator, or mains and a second feeder. The 4 push-buttons and LCD screen let you set automatic or manual mode, read status, and override locally. Inside a panel, it bolts to a plate or clips to DIN rail; the 351 mm width means it needs a full 19-inch sub-panel bay or a dedicated enclosure section. The 95 mm depth keeps it shallow enough for most 600 mm deep enclosures. The uninterrupted duty rating means it's designed to carry load continuously, not just during transfer events.