What it is and what it does
The Siemens 3VA1120-6EF32-0CC0 is a SENTRON molded case circuit breaker (MCCB) for line protection in distribution panels. Rated continuous current Iu is 20 A, and it holds that rating flat from 40 °C up to 50 °C, then derates to 18 A at 70 °C — useful when the breaker sits in a warm cabinet near other heat sources. Breaking capacity runs from 220 kA at 240 V down to 17 kA at 690 V, so it handles high-fault utility feeds without cascading upstream. This is a 3-pole unit with an undervoltage release (UVR) and two HQ auxiliary switches built in. The overcurrent release is thermal-magnetic type TM240. No communication module, no voltage trip, no ground-fault monitoring — it's a straightforward line-protection breaker for fixed-distribution duty.
Physical fit and integration
Dimensions are 70 mm deep, 76.2 mm wide, 130 mm tall — a standard 3-pole MCCB footprint for DIN-rail or panel-mount enclosures. Front protection is IP40, so it's fine for indoor switchgear but not washdown areas. The auxiliary trip is a separate order (3VA9608-0BB24), not included in the box.