Line protection MCCB with headroom to 121 kA
The Siemens SENTRON 3VM1140-4ED22-0AA0 is a 2-pole molded case circuit breaker (MCCB) rated 40 A continuous at 40 °C, with a TM210 thermal-magnetic overcurrent release configured for LI (long-time and instantaneous) protection. It carries a 121 kA interrupting rating at 240 V AC and 76 kA at 415 V AC — S-class switching capacity that covers most industrial service-entrance and feeder applications without needing a current-limiting fuse upstream. The 500 V rated insulation voltage (Ui) and IP40 front protection suit it for panel-mount installation in a dry, enclosed environment.
What the ratings mean for your panel
The 40 A rating holds flat from 40 °C through 50 °C, then derates only 1 A per 5 °C step to 37 A at 70 °C (–) — minimal thermal compression, so you don't oversize the frame for a warm cabinet. The TM210 release's instantaneous pickup is adjustable up to 400 A, letting you tune short-circuit protection to the connected load's inrush without nuisance tripping. Power loss is 7 W maximum, negligible for panel thermal budgeting but worth noting if you're packing multiple breakers in a sealed enclosure.
Physical fit and panel integration
Dimensions are 70 mm deep, 50.8 mm wide, and 130 mm high — a compact 2-pole footprint that mounts on a DIN rail or directly to a backplate. The IP40 front means it's protected against tools and wires >1 mm entering the breaker face, standard for enclosed panel gear. No auxiliary contact slots are populated from the factory; if you need status feedback, plan for an external auxiliary switch block.
DC capability and environmental range
Maximum rated operational voltage on DC is 250 V — usable for DC distribution in control panels or battery-backed circuits. Operating temperature spans -25 °C to 70 °C, storage from -40 °C to 80 °C. The design reference code per IEC 81346-2 is Q, which maps to circuit-breaker function in a standardized panel labeling scheme.