The ABB 1SDA054436R1 is a T5N400TMA320 molded case circuit breaker (MCCB) from the Tmax T5 series, fitted with a fixed thermal-magnetic trip unit rated at 320 A. This is a current-production part — the lifecycle stage is listed as current, meaning it remains in active manufacture and supply.
What the 320 A TMA trip means for fit
The TMA designation indicates a thermal-magnetic trip — the thermal element protects against sustained overloads (cable heating, moderate overcurrents), while the magnetic element handles short-circuit faults with instantaneous response. The 320 A rating sets the continuous current limit; for motor or transformer feeder applications, size the upstream cable and downstream load so the full-load current stays below this threshold. The T5N400 frame carries a 400 A maximum frame rating, so this breaker is a 320 A fixed-trip variant within that frame — no interchangeable trip units, which simplifies BOM but locks the rating.
Panel and deployment context
The T5N400 frame mounts on a DIN rail or directly to a backplate via the standard MCCB footprint. In a distribution panel, it occupies a single module width for the frame size. The fixed thermal-magnetic trip means no field adjustment of the current setting — specify the exact 320 A rating at the design stage. For selective coordination studies, the TMA trip curve data is available from ABB's documentation set.