What this MCCB is and what it does
The Siemens 3VA2225-6HL32-0KA0 is a SENTRON molded case circuit breaker (MCCB) with 3 poles, rated for a continuous current of 250 A at 40 °C and an insulation voltage of 800 V. It's configured for line protection and carries an ETU320 electronic overcurrent release, which gives you adjustable thermal and magnetic trip curves for coordinating with downstream feeders. The shunt trip (STL) allows remote tripping from a pushbutton or safety circuit — useful when you need to kill power from a panel door without reaching the breaker handle.
Breaking capacity — what the numbers mean for your fault level
This MCCB carries a 242 kA breaking capacity at 240 V, dropping to 187 kA at 415 V and 440 V, then 121 kA at 500 V, and 6 kA at 690 V. The 242 kA figure at 240 V means it can safely interrupt a fault current up to 242,000 amps at the lower voltage — that's typical for high-capacity transformer secondaries or large busway feeds. At 690 V the capacity drops to 6 kA, so if your circuit runs at that voltage, make sure your available fault current stays under that limit. The ETU320 release coordinates with these ratings, so the breaker clears fast enough to protect downstream gear without letting the arc sustain.
Thermal derating — when the panel runs hot
The 250 A rating holds steady up to 50 °C ambient — that's the sweet spot. Above that it starts to taper: 241 A at 55 °C, 232 A at 60 °C, 222 A at 65 °C, and 213 A at 70 °C. If your panel sits in a warm enclosure or near other heat sources, size the load accordingly. The maximum operating temperature is 70 °C, and storage range goes from -40 °C to 80 °C. Power loss at full load is 48 W — that's heat that has to leave the enclosure, so factor it into your ventilation or cooling plan.
Mounting and panel fit
The 3VA2225-6HL32-0KA0 measures 105 mm wide, 181 mm high, and 86 mm deep — that's a standard 3-pole MCCB footprint for this current class. It mounts on a DIN rail or can be screw-fastened to a backplate. The depth of 86 mm means it clears most standard enclosure depths, but check your gland plate clearance if you're running cables behind the breaker. No auxiliary contacts are included on this variant, so if you need status feedback to a PLC or alarm panel, you'll add the 3VA9688-0BL33 auxiliary trip block separately.