250 A MCCB with 440 kA SCCR — what that means for your panel
The Siemens SENTRON 3VA2225-8HL32-0CL0 is a 3-pole molded case circuit breaker rated for 250 A continuous current (Iu) and a 440 kA interrupting capacity at 240 V AC — that SCCR figure drops to 330 kA at 415 V and 440 V, then 242 kA at 500 V, and 50.4 kA at 690 V. For a sourcing buyer, the 440 kA at 240 V means this breaker handles fault currents at the main distribution level where the utility transformer can deliver massive short-circuit energy; you need that headroom to avoid cascading failure upstream. The 250 A frame is sized for a feeder or a large motor branch circuit, and the ETU320 electronic trip unit gives you adjustable long-time, short-time, instantaneous, and ground-fault protection curves — not a fixed thermal-magnetic, so you can coordinate selectively with downstream breakers. Deployment context: this mounts in a standard switchboard or panel enclosure on a DIN rail or bolted bus connection — the 105 mm width and 181 mm height fit the SENTRON 3VA frame footprint, and the 86 mm depth leaves room for cable bending radius behind the breaker.
Derating and thermal management
The 250 A rating holds flat from 40 °C up to 50 °C ambient — no derating needed in a typical 40 °C panel. At 55 °C it drops to 241 A, at 60 °C to 232 A, at 65 °C to 222 A, and at 70 °C to 213 A. If your enclosure runs hot (say, a packed panel with multiple breakers), factor in that 213 A at 70 °C is the floor. Maximum power loss is 50.5 W — that heat has to be dissipated through the enclosure walls or forced ventilation. Operating range is -25 °C to 70 °C, storage -40 °C to 80 °C.
Auxiliary and trip accessories
This variant ships with an undervoltage release (UVR) — if control power drops, the breaker trips, which is standard for safety circuits and emergency-stop chains. The auxiliary contact block includes 2 auxiliary switches, 1 trip alarm switch, and 1 electrical alarm switch (HQ type). That gives you status feedback for PLC or SCADA: one set for breaker open/closed, one for trip condition, and one for electrical alarm. The basic switch is order code 3VA2225-8HL32-0AA0; the integrated auxiliary trip is 3VA9608-0BB24 — useful if you need to order spares or replacement sub-assemblies.