What this MCCB delivers
The SENTRON 3VM1112-3ED42-0AA0 is a 4-pole molded case circuit breaker rated for 125 A continuous current across 40 °C to 50 °C ambient, with a TM210 thermal-magnetic release that handles overload and short-circuit protection in one device. Breaking capacity runs 76 kA at 240 V AC, dropping to 53 kA at 415 V, 32 kA at 440 V, and 12 kA at 500 V — match the available fault current at your service voltage to confirm adequate SCCR headroom. Rated insulation voltage is 800 V, with a maximum operating voltage of 690 V AC and 500 V DC.
Thermal derating and panel fit
The 125 A rating holds flat to 50 °C; above that it derates to 122 A at 55 °C, 120 A at 60 °C, 117 A at 65 °C, and 114 A at 70 °C. If your panel ambient runs hot, factor the 55 °C+ curve into the feeder sizing. Dimensions are 101.6 mm wide, 130 mm tall, and 70 mm deep — a 4-pole MCCB that fits standard distribution panel gutters. IP40 on the front means it's protected against tools and small wires entering the breaker face, but the enclosure itself handles the overall ingress rating. Maximum power loss is 23 W at rated load — a figure to check against your enclosure thermal budget if the panel is tightly packed.