125 A MCCB with TM210 release — what the ratings mean for your panel
The Siemens SENTRON 3VA1112-3GD46-0AA0 is a 4-pole molded case circuit breaker (MCCB) rated for line protection at 125 A continuous current (Iu) at 40 °C. That 125 A holds flat through 50 °C — only starts to derate at 55 °C (122 A) and reaches 114 A at 70 °C, so in a warm enclosure you still get most of the rating. The TM210 thermal-magnetic release handles overload and short-circuit protection in one package; no electronic trip unit to program, no auxiliary power needed. Breaking capacity is where this breaker earns its keep in high-fault installations: 75.6 kA at 240 V, 52.5 kA at 415 V, 32 kA at 440 V, and still 11.9 kA at 690 V. That covers most industrial distribution panels fed by transformers in the 1–2 MVA range. The 800 V rated insulation voltage (Ui) gives headroom for 690 V line-to-line systems without creeping along the edge of the insulation spec.
Panel fit and integration
Dimensions: 130 mm height, 101.6 mm width, 70 mm depth. That's a standard 4-pole MCCB footprint for the 125 A frame size — mounts on a DIN rail or screws directly to a backplate. The front face carries IP40 protection, so it's fine in a closed cabinet; no special gasketing needed for the operator panel.
What the TM210 release means for selectivity
The TM210 is a fixed thermal-magnetic release — thermal element for overload, magnetic for short-circuit. No adjustable trip settings, no communication module (this variant has no communication function). That keeps it simple and reliable for line protection where you don't need remote monitoring or adjustable curves. Power loss is 28.1 W maximum at rated current — factor that into enclosure thermal calculations if you're stacking several breakers.