What this MCCB delivers on the panel
The Siemens SENTRON 3VA1025-4ED32-0KH0 is a 3-pole molded case circuit breaker rated for line protection, carrying a continuous current of 25 A up to 50 °C ambient before any derating applies. Above that, the thermal curve pulls the rating down to 23 A at 70 °C — a detail the thermal coordination study needs, not just the nameplate number. Breaking capacity hits 121 kA at 240 VAC and still holds 75.6 kA at 415 VAC, so it handles high-fault commercial and light-industrial service entrances without cascading upstream. Rated insulation voltage is 800 V, giving headroom for 480/277 V or 600 V systems common in North American and European panels. The breaker ships with a built-in shunt trip (STL) and provisions for two auxiliary switches plus a trip alarm switch — enough for remote status and emergency-off integration without an add-on module.
Sizing and selectivity for the electrical engineer
At 25 A continuous with a 121 kA interrupting rating at 240 V, this MCCB sits in the sweet spot for feeder protection downstream of a larger main. The 3VA1025-4ED32-0KH0 is a line-protection device — no ground-fault monitoring, no communication module, no undervoltage release. If the BOM calls for those features, the 3VA1110-5ED36-0AC0 sibling adds electronic trip and communication, but at a higher amp frame. For a straight thermal-magnetic feeder breaker with shunt trip, this order code is the leaner fit.
Panel integration notes
At 70 mm deep, 76.2 mm wide, and 130 mm tall, this 3-pole MCCB fits standard SENTRON mounting footprints. The 76.2 mm width is three 25.4 mm pole pitches — matches the busbar and DIN-rail adapter pattern used across the 3VA line. Terminal lugs accept copper or aluminum conductors up to the rated cross-section; torque values are on the nameplate. No communication wiring needed — the shunt trip takes two control wires, the auxiliary switches add four more for status feedback to the PLC or annunciator.