What this MCCB does and where the ratings matter
The Siemens 3VA1110-5FE46-0AA0 is a 4-pole SENTRON molded case circuit breaker rated 50 A continuous, with a TM220 thermal-magnetic trip unit — the thermal element handles overloads, the magnetic element clears short-circuits. The 187 kA breaking capacity at 240 V is the headline number, but the real-world fit depends on the voltage at your fault point: at 415 V it interrupts 121 kA, at 440 V it drops to 75.6 kA, and at 500 V or 690 V it holds at 17 kA. If your panel feeds a 480 V distribution bus, the 75.6 kA at 440 V is the closest published figure — verify your available fault current against that curve before committing the BOM line. The 800 V rated insulation voltage (Ui) tells you the breaker is designed for 480/277 V and 600 V systems with margin, but the 690 V breaking capacity is only 17 kA — so if you are protecting a 690 V motor drive, confirm the SCCR of the downstream equipment is coordinated with that figure.
Temperature derating — don't ignore it
The 50 A rating holds at 40 °C, 45 °C, and 50 °C without derating. At 55 °C it drops to 98 A, at 60 °C to 96 A, at 65 °C to 94 A, and at 70 °C to 91 A. If this breaker lives in a non-air-conditioned enclosure near a heat source — say, next to a drive or transformer — apply the 70 °C figure (91 A) as your continuous current limit, not the nameplate 50 A. The thermal trip element responds to ambient temperature; packing the panel full of breakers without ventilation will nuisance-trip the 50 A setting long before the load hits 50 A.
Panel fit and mounting
The breaker measures 130 mm high, 101.6 mm wide, and 70 mm deep. Four-pole at 101.6 mm wide — that is a standard 4-inch footprint, so it fits a typical 4-pole MCCB slot in a Siemens SENTRON panelboard or a DIN-rail adapter. The IP40 front protection means it is splash-resistant from the front but not sealed against hose-down; keep it inside a rated enclosure for washdown areas.