What it is and what it does
The SENTRON 3VA1225-5EF32-0BB0 is a 3-pole molded case circuit breaker (MCCB) rated for line protection, fitted with an undervoltage release (UVR) and two HP auxiliary switches. It carries a continuous current rating of 250 A at ambient temperatures up to 50 °C, derating to 223 A at 70 °C — the thermal curve governs real-world loading in a warm panel. Breaking capacity hits 187 kA at 240 V, 121 kA at 415 V, 75.6 kA at 440 V, 30 kA at 500 V, and 17 kA at 690 V — that range covers most industrial distribution bus voltages without needing a current-limiting upstream breaker. Rated insulation voltage is 800 V, and the breaker operates from -25 °C to 70 °C ambient, with storage from -40 °C to 80 °C.
Panel fit and integration
Dimensions are 105 mm wide, 158 mm high, 70 mm deep — fits standard MCCB panel cutouts and busbar arrangements for 3-pole frames at this rating. The basic switch module is order code 3VA12255EF320AA0; the auxiliary release is an undervoltage release (UVR), wired separately from the main power path. Maximum power loss is 59.5 W — factor that into enclosure thermal calculations if the breaker is tightly grouped.