What this MCCB carries and where it fits
The Siemens SENTRON 3VA1050-4ED42-0CH0 is a 4-pole molded case circuit breaker (MCCB) rated for 50 A at 40 °C, with a breaking capacity of 121 kA at 240 V AC. It's designed for line protection in distribution panels — the high interrupt rating at 240 V makes it a fit for main or feeder positions where fault currents are substantial. The 4-pole configuration covers three-phase-plus-neutral or three-phase with a switched neutral, common in North American and IEC panel builds. Rated insulation voltage is 800 V, so the breaker can sit in 480/277 V or 600 V systems without derating the insulation path. The thermal-magnetic trip holds 50 A continuous through 55 °C, then derates to 49 A at 55 °C and 45 A at 70 °C — useful to know if the breaker lands in a hot enclosure or next to other heat sources. This unit includes an undervoltage release (UVR) that will trip the breaker if supply voltage drops below a set threshold — a standard requirement for safety circuits that need to drop power on loss of control voltage. It also carries 2 auxiliary switches plus 1 trip alarm switch (HQ), giving status feedback for remote monitoring or PLC inputs.
Breaking capacity across voltage levels
The 3VA1050-4ED42-0CH0 delivers 121 kA at 240 V, 75.6 kA at 415 V, 52.5 kA at 440 V, and 11.9 kA at both 500 V and 690 V. That's a steep drop above 440 V — at 690 V the interrupt rating is 11.9 kA, so verify the available fault current at the point of installation. For 480 V systems the 52.5 kA at 440 V is the closest reference; actual performance at 480 V will be between the 440 V and 500 V figures.
Panel fit and dimensions
The breaker measures 130 mm high, 101.6 mm wide, and 70 mm deep — a 4-pole MCCB in a compact footprint that fits standard Siemens 3VA mounting plates and busbar systems. The 70 mm depth is shallow enough for most 200 mm deep enclosures without crowding the door or wiring gutters.