What this MCCB is and what the key ratings mean for your panel
The Siemens SENTRON 3VA1050-4ED36-0AC0 is a 3-pole molded case circuit breaker (MCCB) rated for a continuous current Iu of 50 A, designated for line protection. The interrupting ratings tell you where this breaker can be applied: 121 kA at 240 V, 75.6 kA at 415 V, 52.5 kA at 440 V, and 11.9 kA at 690 V. These are the maximum fault currents the breaker can safely clear at each voltage level — critical for verifying SCCR headroom and selectivity coordination downstream. The TM210 overcurrent release means it uses a fixed thermal-magnetic trip curve, not an electronic one; no field adjustment of the long-time pickup, so the 50 A rating is the setting. Thermal derating is modest: the breaker holds 50 A from 40 °C through 50 °C ambient, then drops to 48 A at 55 °C, 47 A at 60 °C, 46 A at 65 °C, and 45 A at 70 °C. For a panel that runs hot — say, 55 °C inside the enclosure — you lose 2 A of headroom. The operating temperature range is -25 °C to 70 °C, with storage from -40 °C to 80 °C. Mechanical endurance is rated at 15,000 operations (latching cycles). The auxiliary contact version ships with 2 HQ switches.
Panel integration and mounting
Mounts on a DIN rail or directly to a mounting plate via the 3VA screw-mount kit. The width is 76.2 mm (roughly 3 standard module widths on a 25 mm grid), depth 70 mm, height 130 mm. Front-face protection class is IP40 — suitable for a dry indoor panel; not rated for washdown. The 3-pole design fits a 3-phase distribution board; the line-protection designation means it is intended for feeder or branch-circuit protection, not motor-starting duty (no adjustable overload curve for motor inrush).
Selectivity and coordination note
The interrupting ratings across multiple voltage levels (121 kA at 240 V down to 11.9 kA at 690 V) let the designer verify full-selectivity with upstream breakers at each fault-current level. The TM210 release has a fixed long-time delay (tr max. 1 s) and a fixed short-time pickup — no zone-selective interlocking or ground-fault alarm on this variant. For a simple radial feeder where arc-flash energy reduction is not required, this is a clean choice.