What the ratings mean for fit
The Siemens SENTRON 3VA2025-6KP36-0AA0 is a 3-pole molded case circuit breaker rated for 25 A continuous current across the full ambient range from 40 °C to 70 °C — no derating needed up to that ceiling, which simplifies panel thermal budgeting in a warm enclosure. Its interrupting capacity hits 242 kA at 240 V and 187 kA at 415 V, dropping to 3 kA at 690 V; that 242 kA figure at 240 V means it can clear a fault on a high-capacity transformer secondary without the breaker welding shut, a key selectivity gate for main or feeder positions. The ETU850 electronic release gives adjustable long-time, short-time, and instantaneous pickup bands, plus a communication function for remote trip indication or load monitoring — useful when the breaker sits in a monitored distribution panel and you want event logs without a separate power meter.
Panel integration and mounting
At 105 mm wide, 181 mm tall, and 86 mm deep, this breaker fits standard MCCB panel cutouts and bus-bar centers for 3-pole frames. The IP40 front protection means it's suited for enclosed distribution boards where the door or cover shields the breaker face; no washdown rating, so keep it out of wet zones. The 0.84 W maximum power loss at rated current is low enough that multiple breakers can be ganged in a row without forced ventilation in most panel layouts.