What the ratings mean for fit
The Siemens SENTRON 3VA1120-6EF36-0HH0 is a 3-pole molded case circuit breaker (MCCB) rated for line protection. It carries 20 A continuously at 40 °C ambient, derating to 19 A at 65 °C — so in a warm panel you lose one amp, not the whole rating. The headline number is the interrupting capacity: 220 kA at 240 VAC, 154 kA at 415 V, 121 kA at 440 V, and 17 kA at both 500 V and 690 V. That means it can clear a fault at those levels without welding its contacts or rupturing the case, which is the deciding spec for high-fault panels near large transformers or motor control centers. Insulation voltage is rated 800 V, so it's comfortable in 480 V and 600 V class systems with headroom.
Integration and accessories
This breaker ships with a shunt trip (STL) release and an auxiliary switch block: 2 auxiliary switches plus 1 trip alarm switch (HQ designation). The supplied basic switch is order code 3VA11206EF360AA0. No undervoltage release, no ground-fault monitoring, no communication module — it's a straightforward line-protection device meant for a panel where you need remote trip capability and status feedback, not networked power monitoring. Dimensions are 76.2 mm wide, 130 mm tall, 70 mm deep — standard 3-pole MCCB footprint for DIN-rail or panel-mount integration.