What the ratings mean for fit
The Siemens 3VA1112-5EE46-0AA0 is a SENTRON molded case circuit breaker (MCCB) built for line protection — the primary feeder or distribution breaker in a panel, not a motor-protective device. Four poles give you switched neutral or three-phase-plus-neutral capability, which matters for TN-S or TN-C-S systems where you need the neutral isolated and protected. Rated 125 A continuous at 40 °C ambient, and it holds that same 125 A through 50 °C — no derating needed in a warm enclosure. Above 50 °C the curve starts to bite: 122 A at 55 °C, 120 A at 60 °C, stepping down to 114 A at 70 °C. If your panel runs hot, size the load to the 70 °C figure, not the nameplate. Breaking capacity is the headline: 187 kA at 240 V AC, 121 kA at 415 V, 75.6 kA at 440 V, and 17 kA at both 500 V and 690 V. That 187 kA at 240 V is a high-interrupting rating — it will clear a bolted fault on a large transformer secondary without the arc flashing over. At 690 V the 17 kA is still respectable for industrial distribution, but you need to verify the available fault current at that voltage level. The TM220 trip unit is thermal-magnetic — fixed thermal element for overload, fixed magnetic for short-circuit. No electronic adjustment, no communication, no ground-fault monitoring. It's a workhorse breaker for straightforward distribution where you don't need selectivity tuning or remote status. Insulation voltage rated 800 V. Max power loss is 28.1 W per pole.
Panel fit and footprint
Dimensions are 130 mm high, 101.6 mm wide, 70 mm deep. The 4-pole width of roughly 4 inches is standard for this frame size — it occupies the same DIN-rail or mounting-plate footprint as the 3VA1112-5EE32-0AA0 (the 3-pole sibling), so a panel laid out for the 3-pole version has room for this 4-pole if you shift the adjacent devices by one pole width.