What this MCCB carries and what it means for your panel
The Siemens SENTRON 3VA1125-5EF36-0HA0 is a 3-pole molded case circuit breaker rated 25 A at 40 °C, with a shunt trip release (STL) for remote tripping and a TM240 thermal-magnetic overcurrent release. It is designed for line protection — the primary role is feeding a distribution bus or a dedicated load, not motor or generator protection. The 187 kA interrupting rating at 240 V is the headline number for fault duty; at 415 V it still breaks 121 kA, and at 690 V it holds 17 kA, which covers most industrial service-entrance and sub-distribution applications where the available fault current is high. The 70 mm depth and 76.2 mm width fit a standard SENTRON 3VA panel footprint — it swaps in without re-drilling the mounting plate or re-routing the bus bars.
Thermal derating and real-world current
The 25 A rating holds flat from 40 °C through 50 °C — no derating needed in a warm enclosure. At 55 °C it drops to 24 A, at 65 °C to 23 A, and at 70 °C it still carries 23 A. That means a panel running at 50 °C ambient can use the full 25 A continuous; only above that do you need to account for the 1 A steps. The maximum power loss is 8.5 W, which is modest for a 3-pole 25 A MCCB and won't drive extra ventilation in a typical distribution panel.
Panel fit and integration notes
The 3VA1125-5EF36-0HA0 mounts on a DIN rail or direct panel surface via the SENTRON base. Dimensions are 130 mm height, 76.2 mm width, 70 mm depth — the 3-pole width matches the standard 3VA frame. The shunt trip release (STL) is factory-fitted; no field kit required. No communication function, no undervoltage release, no ground-fault monitoring on this variant — it is a straight line-protection breaker with remote trip capability. The TM240 thermal-magnetic release provides fixed thermal and magnetic trip settings; there is no trip indicator on the front face.