The Siemens SENTRON 3VA1125-3EF32-0DH0 is a 3-pole molded case circuit breaker (MCCB) rated 25 A at 40 °C, with a breaking capacity of 75.6 kA at 240 V. It's designed for line protection in distribution panels, and the 70 mm depth and 76.2 mm width mean it fits standard SENTRON mounting footprints — no panel rework needed if you're swapping from an earlier 3VA frame.
Ratings and what they mean for fit
The 25 A rating holds steady from 40 °C up to 50 °C, then derates to 24 A at 55–60 °C and 23 A at 65–70 °C — so if your panel ambient runs hot, you lose 1–2 A of headroom. Breaking capacity drops from 75.6 kA at 240 V to 52.5 kA at 415 V, then to 32 kA at 440 V, and further to 11.9 kA at 500 V and 690 V. That 11.9 kA at 690 V is the floor — still enough for most industrial secondary distribution, but verify coordination if your fault current exceeds that. The insulation voltage is rated 800 V, so the breaker is physically capable of 690 V line-to-line service — the 11.9 kA at 690 V is the limiting factor, not the insulation.
Built-in accessories and deployment
This variant ships with an undervoltage release (UVR) and a set of auxiliary switches: 2 auxiliary switches plus 1 trip alarm switch (HQ). The UVR means the breaker drops out when control voltage is lost — typical for emergency-stop or safety circuits where a loss of signal should kill power. No communication module, no ground-fault monitoring — this is a pure line-protection MCCB. The trip indicator (mechanical flag) gives a clear visual when it's tripped, which speeds fault isolation on a panel walk-through. Operating temperature range is -25 °C to 70 °C; storage from -40 °C to 80 °C. Maximum power loss is 11 W — negligible for panel thermal budgeting, but worth noting if you're packing multiple breakers in a sealed enclosure.