What this MCCB brings to the panel
The Siemens 3VA1120-4EF32-0HA0 is a SENTRON molded case circuit breaker sized for line protection in a 3-pole, 20 A footprint. It carries a TM240 thermal-magnetic overcurrent release and a built-in shunt trip (STL) for remote opening, which means you can wire it into an emergency-stop or safety circuit without adding an external trip module. Rated 20 A continuously at 40 °C, and it holds that rating all the way up to 55 °C — only drops to 19 A at 60–70 °C. That thermal stability is useful if the breaker sits next to other heat sources in a crowded enclosure; you won't have to oversize the frame just to keep it from nuisance-tripping on a warm day. Interrupting capacity is 121 kA at 240 V, 75.6 kA at 415 V, and still 52.5 kA at 440 V. That's high-end fault-clearing for a 20 A frame — it lets you place this breaker close to a transformer or large motor branch without worrying about through-fault damage downstream.
Sizing and coordination notes
Insulation voltage is rated 800 V. The 3-pole design handles three-phase loads; the shunt trip (STL) release is factory-fitted.
Panel fit and dimensions
The breaker measures 130 mm tall, 76.2 mm wide, and 70 mm deep — a standard 3-pole MCCB footprint that drops into most SENTRON panelboards and DIN-rail adapters without re-drilling. Maximum power dissipation is 12 W, so it won't overheat a sealed enclosure if you account for that heat load in your thermal design.