Siemens 3VA1225-5GF42-0KH0 — 250 A SENTRON MCCB for Line Protection
The Siemens 3VA1225-5GF42-0KH0 is a 4-pole SENTRON molded case circuit breaker rated at 250 A continuous, with an interrupting capacity of 187 kA at 240 V and 121 kA at 415 V. It is designed for line protection in distribution panels, meaning it sits upstream protecting feeders and busbars rather than a specific motor or load. The 250 A rating holds from 40 °C up to 50 °C without derating; above that it steps down to 243 A at 55 °C and 223 A at 70 °C — useful to know if the breaker lands in a hot top-of-panel location.
Interrupting Capacity and Selectivity Headroom
The 187 kA at 240 V is the highest short-circuit rating on this frame; at 415 V it still delivers 121 kA, and at 690 V it holds 17 kA. For a site electrical engineer coordinating a distribution board, that means this MCCB can be placed at the main incomer where fault current is highest, and still coordinate with downstream 25 kA or 36 kA breakers — the 187 kA figure gives selectivity headroom without needing a current-limiting fuse upstream. The 800 V rated insulation voltage confirms it is rated for 690 V line-to-line systems.
Built-in Auxiliary Switches and Shunt Trip
This variant ships with 2 auxiliary switches plus a trip alarm switch (HQ), and a shunt trip release (STL) for remote tripping. The trip indicator and voltage trigger are both present, so you get local mechanical indication and the ability to wire the shunt trip into an E-stop or PLC-based safety circuit. No undervoltage release is fitted — if you need UVR for a machine safety loop, this is not the variant.
Physical Fit and Panel Integration
Dimensions are 158 mm high, 140 mm wide, 70 mm deep (–). The 140 mm width is the 4-pole frame footprint — it occupies four modular pole spaces on a DIN rail or panel-mount base. Depth of 70 mm is shallow enough for most 200 mm deep enclosures; verify gland-plate clearance if the breaker is rear-wired. Power loss at full load is 57 W, so factor that into the enclosure thermal budget.