What this MCCB is and what it's for
The Siemens 3VA1050-4ED42-0CA0 is a SENTRON molded case circuit breaker (MCCB) designed for line protection in distribution panels and industrial switchboards. With 4 poles and a TM210 thermal-magnetic trip unit, it handles 50 A continuously at 40 °C and can break up to 121 kA at 240 V AC — that's the interrupting capacity you need for high-fault service-entrance or sub-distribution applications where the available fault current is substantial.
Breaking capacity across the voltage range
The interrupting rating drops as voltage rises: 75.6 kA at 415 V, 52.5 kA at 440 V, and 11.9 kA at both 500 V and 690 V. That 11.9 kA floor at 690 V is the number to check if you're feeding a 690 V motor control center — it's still adequate for most industrial MCC applications, but verify your worst-case bolted-fault calculation against that figure.
Temperature derating and continuous current
The 50 A rating holds from 40 °C through 50 °C without derating. Above that, it steps down: 49 A at 55 °C, 48 A at 60 °C, 46 A at 65 °C, and 45 A at 70 °C. If your panel ambient runs above 50 °C, size the breaker for the derated value — not the 50 A nameplate.
Built-in undervoltage release
This variant ships with an undervoltage release (UVR) — the auxiliary release type is identified as undervoltage release in the design. That means the breaker trips automatically if the control voltage drops below a set threshold, which is standard for machinery safety circuits where a loss of control power must open the main disconnect. No separate UVR module to wire in.
Physical fit in the panel
Dimensions are 101.6 mm wide, 130 mm tall, and 70 mm deep — a standard 4-pole MCCB footprint that fits most DIN-rail or panel-mount enclosures. The 70 mm depth is shallow enough for most wall-mount distribution boards; check gland-plate clearance if you're back-paneling with deep cable ducts.