What this MCCB is and what it carries
The Siemens 3VA2110-5KP42-0AA0 is a SENTRON molded case circuit breaker (MCCB) rated for line protection, with a continuous current Iu of 100 A across the full ambient range from 40 °C to 70 °C — no derating needed up to that ceiling. Four poles, electronic overcurrent release type ETU850, and a communication function onboard for integration into a monitored distribution system. The rated insulation voltage Ui is 800 V, so it sits comfortably in 400 V and 690 V panels without creeping along insulation boundaries.
Breaking capacity — what the numbers mean for selectivity
The interrupting ratings climb with the voltage drop: 187 kA at 240 V, 121 kA at 415 V and 440 V, 75.6 kA at 500 V, and 3.7 kA at 690 V. That 187 kA figure at 240 V is high enough for most secondary-side transformer feeds or large UPS bypass panels; the 121 kA at 415 V covers heavy industrial main feeders. At 690 V the rating drops to 3.7 kA — still adequate for motor branch circuits where fault current is lower, but not for a main on a high-capacity 690 V bus. Coordination studies should use the 415 V or 440 V curve for typical 400 V-class systems.
Panel fit and environmental limits
Dimensions: 181 mm high, 140 mm wide, 86 mm deep. That depth (86 mm) is shallow enough for most standard distribution boards; the 140 mm width for a 4-pole unit is typical for the SENTRON 3VA2 frame. Front protection is IP40 — fine for a closed panel, but not for washdown zones. Operating temperature range -25 °C to 70 °C, storage from -40 °C to 80 °C. Power loss at rated current is 10 W maximum — negligible for thermal budgeting inside a cabinet, but worth noting if you pack several units side by side without forced ventilation.