What this MCCB carries on the nameplate
The 3VA1120-6EF32-0KC0 is a Siemens SENTRON 3VA1 molded case circuit breaker (MCCB) for line protection, rated 20 A at 40 °C and 3-pole. Its interrupting capacity hits 220 kA at 240 VAC, 154 kA at 415 V, 121 kA at 440 V, and 17 kA at 500 V or 690 V — so the 240 V figure is the headline, but the 415 V rating is what matters for most 400 V-class industrial panels. Insulation voltage is rated 800 V, meaning the internal clearance and creepage support 690 V phase-to-phase systems without derating the insulation. Current rating holds flat at 20 A from 40 °C through 55 °C, then gently steps down to 19 A at 60 °C through 70 °C. That thermal curve means you don't lose headroom in a warm enclosure until you cross 55 °C — common for a panel sitting near a furnace line or in a non-conditioned electrical room.
Integrated accessories — shunt trip and aux switches
This variant ships with a shunt trip (STL) release and two HQ auxiliary switches pre-fitted. The shunt trip lets you remotely trip the breaker from a safety PLC or emergency-stop chain without running control wires to a separate undervoltage release module. The two HQ aux switches provide independent status feedback — one for the open/closed position to the controller, one for the panel HMI or remote SCADA input.
Panel fit and mounting
Footprint is 76.2 mm wide, 130 mm tall, 70 mm deep — a standard 3-pole MCCB width for DIN-rail or screw-mount panels. No communication module on this variant, so no extra width for a bus coupler. The 70 mm depth leaves clearance for rear-connection terminals in a typical 200 mm-deep enclosure.