What this MCCB is and what the ratings mean for your panel
The Siemens 3VA1125-5EF36-0BH0 is a SENTRON molded case circuit breaker (MCCB) sized for line protection in distribution panels. Its 25 A rated continuous current (Iu) holds flat from 40 °C through 50 °C, then derates to 24 A at 55 °C and 22.5 A at 70 °C — so if your enclosure runs hot, you size the load at the 70 °C figure, not the nameplate 25 A. The interrupting ratings are the real story here: 187 kA at 240 V, 121 kA at 415 V, 75.6 kA at 440 V, and 17 kA at 690 V. That 187 kA figure at 240 V means this breaker can safely clear a fault on a high-capacity transformer secondary without upstream fuses needing to coordinate — it's a high-interrupting-capacity (HIC) MCCB, not a standard 25 A frame. At 690 V the 17 kA still covers most industrial motor branch circuits. The TM240 thermal-magnetic release means fixed thermal and magnetic trip settings — no interchangeable trip units, no field adjustment. The undervoltage release (UVR) drops the breaker on loss of control voltage, which is standard for safety circuits that need to guarantee a de-energized state when the control supply fails. The auxiliary contact package includes 2 aux switches plus a separate trip alarm switch (HQ), giving you both position feedback and fault indication without adding external relays.
Panel fit and integration notes
Dimensions are 130 mm high, 76.2 mm wide, 70 mm deep — a standard 3-pole MCCB footprint that drops into most SENTRON panelboards and distribution blocks without re-drilling. The IP40 front protection means it is suitable for indoor panel mounting where no water spray is present; keep it behind the enclosure door. The integrated undervoltage release (UVR) and the 2 aux + 1 alarm switch are factory-fitted in this order code variant. If your BOM calls for a line-protection MCCB with UVR and auxiliary contacts already wired, this is the turnkey variant — no separate accessory ordering or field assembly needed.