What the ratings mean for fit
The Siemens 3VA1112-4ED12-0AA0 is a 1-pole SENTRON molded case circuit breaker rated for 125 A continuous at 45 °C and 50 °C, derating to 114 A at 70 °C. The TM210 thermal-magnetic release provides fixed LI protection — the instantaneous trip (Ii) is fixed at 1250 A, ten times the continuous rating, which gives good inrush headroom for motor or transformer branch circuits without nuisance tripping on startup. Interrupting capacity is 75.6 kA at 240 V AC and 9 kA at 415 V AC — the 240 V figure covers most North American panelboard applications, while the 415 V rating suits IEC distribution where fault currents are lower. The 1-pole format fits standard 25.4 mm (1 in) per-pole width on DIN rail, matching the SENTRON 3VA family footprint for easy retrofit or new build.
Integration and deployment
Mounts on DIN rail in a standard enclosure with IP40 protection on the front face — suitable for dry indoor panel environments. The 70 mm depth (2.76 in) leaves clearance behind the door for wiring and auxiliary accessories. No communication function or motor drive option is fitted on this variant; it is a standalone line-protection breaker.