The Siemens SENTRON 3VA1112-3GE42-0AA0 is a 4-pole molded case circuit breaker (MCCB) rated 125 A at 40 °C, with a TM220 thermal-magnetic release for line protection. Its interrupting capacity reaches 75.6 kA at 240 V AC and 52.5 kA at 415 V AC, making it suited for high-fault panels where selectivity and SCCR headroom matter.
Ratings and what they mean for fit
The 125 A rating holds flat from 40 °C to 50 °C, then derates to 114 A at 70 °C — useful when the breaker sits in a warm enclosure near other heat sources. The 75.6 kA at 240 V AC and 52.5 kA at 415 V AC tell you the breaker can safely interrupt fault currents up to those levels without upstream coordination failure. Rated insulation voltage Ui is 800 V, and operating voltage is 690 V AC, so it covers 480 V and 600 V class systems as well. The TM220 release is a thermal-magnetic design — thermal element handles overloads, magnetic element handles short-circuits. No undervoltage release, no voltage trigger, no communication function, and no ground-fault monitoring on this variant. Power loss is 28.1 W maximum, which matters for enclosure thermal budgeting.
Where it goes in the panel
At 70 mm deep, 101.6 mm wide, and 130 mm tall, the 3VA1112-3GE42-0AA0 fits standard DIN-rail or panel-mount layouts. IP40 on the front means it is protected against solid objects over 1 mm but not sealed against moisture — keep it inside the enclosure, not on a washdown zone. The 4-pole design handles three-phase plus neutral (100 % N-conductor protection).