What this MCCB carries — and what it means on the panel
The Siemens 3VA1050-4ED36-0BH0 is a 3-pole SENTRON molded case circuit breaker rated for 50 A continuous current (Iu) with a TM210 thermal-magnetic overcurrent release. The 50 A rating holds flat from 40 °C through 50 °C, then derates to 48 A at 55 °C and 45 A at 70 °C — so in a warm enclosure you lose about 10 % at the top end. Breaking capacity runs 121 kA at 240 V, 75.6 kA at 415 V, 52.5 kA at 440 V, and 11.9 kA at 690 V. That 415 V figure is the one that matters for most 400 V-class industrial distribution: 75.6 kA covers high-fault utility feeds without needing a current-limiting upstream device. This unit ships with an undervoltage release (UVR) fitted as the auxiliary release, plus 2 auxiliary switches and 1 trip alarm switch (HQ version). The UVR means the breaker drops open if control voltage falls below the dropout threshold — common on safety circuits or E-stop strings where loss of control power should also kill the load. The trip alarm switch gives a separate signal when the breaker trips on fault, not just when manually opened, which is useful for remote annunciation or PLC fault-logging.
Panel fit and integration
Dimensions are 70 mm deep, 76.2 mm wide, 130 mm tall. The 76.2 mm width is a standard 3-pole MCCB footprint — fits most DIN-rail or panel-mount enclosures designed for SENTRON 3VA frames. Front protection is IP40, so it's fine inside a closed cabinet but not for washdown or outdoor exposure without an enclosure. Rated insulation voltage is 800 V, covering 480/600 V systems with margin.