What this MCCB delivers — and what the ratings mean for your panel
The Siemens 3VA1120-5ED32-0AA0 is a 3-pole SENTRON molded case circuit breaker (MCCB) rated 20 A continuous at 40 °C through 55 °C — no derate needed in a warm enclosure unless ambient climbs above 55 °C, where it drops to 19 A at 70 °C. That thermal-magnetic TM210 release handles overloads and short-circuits without an external trip unit. The interrupting rating hits 187 kA at 240 V AC, falling to 121 kA at 415 V and 75.6 kA at 440 V — still high enough for most distribution panel fault levels. At 500 V and 690 V it holds 17 kA, so it's usable on 480/277 V or 600 V systems where available fault current stays under that threshold. Rated insulation voltage is 800 V, and the breaker is designed for line protection (not motor or generator protection) — so it's the right choice for feeder and branch-circuit overcurrent protection in distribution switchboards, panelboards, and downstream subpanels. The IP40 front protection keeps dust and tools out of the mechanism; the rest of the breaker is open to the enclosure, so the panel itself must maintain the required IP rating.
Mounting and integration — fits the standard footprint
The breaker measures 70 mm deep, 76.2 mm wide, and 130 mm high — a standard 3-pole MCCB footprint that drops into existing SENTRON or comparable panel cutouts without panel rework. The TM210 release is fixed, so no separate trip-unit wiring or configuration is needed. Operating temperature range is -25 °C to 70 °C, storage from -40 °C to 80 °C, so it survives cold warehouses and hot enclosures alike. Maximum power loss is 12 W — negligible for thermal budgeting in a ventilated panel.