What this SENTRON MCCB is and where it fits
The Siemens SENTRON 3VA1120-6EF32-0DA0 is a 3-pole molded case circuit breaker (MCCB) rated for line-protection duty — meaning it's the main guard between a transformer or feeder and the downstream distribution, not a motor-protection breaker with thermal-bimetal-only curves. It carries a TM240 overcurrent release, a thermal-magnetic unit with a 240 A fixed magnetic trip threshold, and a continuous current rating of 20 A that holds steady from 40 °C up to 55 °C before it starts to derate at 60 °C. Out here in the grease, that thermal stability means you don't lose headroom just because the panel runs warm near a motor drive or a hot pump. The 220 kA interrupting rating at 240 VAC is the headline figure — that's the short-circuit current it can safely clear at the lowest common industrial voltage. At 415 V it's still 154 kA, at 440 V it's 121 kA, and at 500 V and 690 V it drops to 17 kA. For a panel engineer, that 220 kA number tells you this breaker can sit right behind a large transformer without needing a current-limiting fuse upstream. It's sized for high-fault locations where the available fault current would blow a standard 10 kA or 25 kA MCCB apart.
Undervoltage release and panel integration
This order code includes an undervoltage release (UVR) — the entry confirms it's an undervoltage release (UVR) design. That's a separate shunt-style coil that trips the breaker when the control voltage drops below a set threshold, typically used in safety circuits where a loss of control power must drop the main breaker. If you're wiring a safety-rated panel or an emergency-stop chain that needs to kill the feeder on undervoltage, this UVR saves you an external relay. The breaker itself is 76.2 mm wide, 130 mm tall, and 70 mm deep — standard SENTRON 3VA footprint, so it'll drop into a DIN-rail or screw-mounted panel without re-drilling the backplate. Rated insulation voltage is 800 V, so it's good for 690 V systems with margin. The operating temperature range runs from -25 °C to 70 °C, and storage from -40 °C to 80 °C — fine for a non-conditioned electrical room or a rooftop enclosure. Power dissipation maxes at 14.5 W, which is modest for a 20 A MCCB; no forced cooling needed in a standard panel.