What this MCCB is and what it does in a panel
The Siemens 3VA1110-3EF46-0AA0 is a SENTRON molded case circuit breaker (MCCB) built for line protection in distribution panels and motor control centers. It carries 100 A continuously at 40 °C ambient, and it's a 4-pole unit — meaning it switches all three phases plus the neutral, which you need for four-wire systems or where you want a common trip on all poles. The TM240 overcurrent release gives you thermal-magnetic protection: the thermal element handles overloads, the magnetic element handles short circuits. Breaking capacity hits 75.6 kA at 240 V, 52.5 kA at 415 V, and still holds 11.9 kA at 690 V — that's real fault-current headroom for industrial service where the available fault current can be stiff. Mounts on a DIN rail or panel-mount base, and the front face carries IP40 protection, so it's fine in a clean indoor enclosure but not for washdown areas.
Thermal derating and what it means for your load
This breaker is rated 100 A all the way up to 50 °C — that's a solid continuous rating for most panel interiors. Above that it starts to derate: 98 A at 55 °C, 96 A at 60 °C, 94 A at 65 °C, and 91 A at 70 °C. If your panel sits near a hot motor or in a sun-baked cabinet, that 91 A at 70 °C is the number you size to, not the 100 A label. The maximum power loss is 25 W, so account for that heat in your enclosure thermal calculation. Operating range is -25 °C to 70 °C; storage range is -40 °C to 80 °C.
Footprint and panel fit
Physical dimensions: 130 mm high, 101.6 mm wide, 70 mm deep. That 70 mm depth is shallow enough to fit in a standard 200 mm deep enclosure with room for wiring behind it. The 4-pole width of 101.6 mm means it takes up about four 25 mm module spaces on a DIN rail — check your existing rail layout if you're swapping in a retrofit. No undervoltage release, no communication module, no ground-fault monitoring on this variant — it's a straight thermal-magnetic line-protection breaker.