What this MCCB is and what it does
The Siemens 3VA1225-5GF42-0HA0 is a SENTRON molded case circuit breaker (MCCB) rated for 250 A continuous current across four poles, with a TM240 thermal-magnetic overcurrent release. Its 187 kA breaking capacity at 240 V AC gives you serious fault-current headroom for main feeders or high-capacity branch circuits — that rating means it can safely interrupt a short-circuit fault up to that level without welding contacts or cascading damage upstream. This is a line-protection version, so it's set up for overcurrent and short-circuit protection of cables and busbars, not motor or generator protection. The 4-pole design with 100% N-conductor protection makes it suitable for TN-S or TN-C-S systems where the neutral needs full-rated protection, not a reduced cross-section. The 3VA1225-5GF42-0HA0 includes a shunt trip (STL) auxiliary release for remote tripping — useful in emergency-stop circuits or automated shutdown sequences. The associated auxiliary trip module is order code 3VA9688-0BL30.
Breaking capacity across voltage levels
Breaking capacity drops as system voltage rises: 187 kA at 240 V, 121 kA at 415 V, 36 kA at 440 V, and 17 kA at 690 V. For a 400 V class panel, the 121 kA figure at 415 V gives you comfortable headroom above typical 50-65 kA SCCR requirements for most industrial switchboards. At 690 V the 17 kA rating still covers many motor control center applications.
Current derating and thermal limits
The 250 A rating holds flat from 40 °C through 50 °C. Above that it derates: 243.3 A at 55 °C, 236.5 A at 60 °C, 229 A at 65 °C, and 223 A at 70 °C. If your panel ambient runs hot — say near a row of drives or transformers — factor in that 223 A floor at 70 °C. Operating temperature range is -25 °C to +70 °C; storage range is -40 °C to +80 °C.
Panel fit and mounting
Dimensions: 70 mm deep, 140 mm wide, 158 mm high.