What this 4-pole MCCB carries — and where the ratings matter
The Siemens SENTRON 3VA1050-2ED42-0DC0 is a 4-pole molded case circuit breaker (MCCB) rated for 50 A continuous current at 40 °C, with a TM210 thermal-magnetic overcurrent release and an integrated undervoltage release (UVR). Interrupting capacity scales with system voltage: 52.5 kA at 240 V, 32 kA at 415 V, 13.6 kA at 440 V, and 7.5 kA at 690 V — so the same frame covers 480Y/277 V panels and 690 V motor circuits, but the available fault current at the board must stay under the curve for the tap voltage. Thermal derating is flat through 50 °C (still 50 A), then drops to 48 A at 55 °C and 45 A at 70 °C — useful when the breaker sits in a crowded enclosure near other heat sources; the 70 °C operating max matches the upper ambient limit. Rated insulation voltage is 800 V, and the front face carries IP40 protection — fine for a clean panel interior; no IP rating on the sides or back, so it relies on the enclosure for splash or dust.
Panel fit and auxiliary wiring
Dimensions are 70 mm deep, 101.6 mm wide, and 130 mm high — the 101.6 mm width is the standard 4-pole MCCB footprint for this SENTRON frame size, so it drops into existing 3VA panel layouts without re-drilling the mounting plate. Comes factory-fitted with 2 HQ auxiliary switches (changeover contacts) for status feedback to a PLC or indication lamp; the auxiliary trip accessory is order code 3VA9608-0BB25. No communication module, no phase-failure detection, no ground-fault monitoring — this is a plain line-protection MCCB with undervoltage release only.
Lifecycle and sourcing reality
Latching endurance is rated at 15 000 operations — typical for a 50 A frame in panelboard duty; not a high-cycle motor-switching breaker, but fine for infrequent manual disconnect and fault clearing.