What this 250 A MCCB does on the line
The Siemens SENTRON 3VA2325-6HL32-0HH0 is a 3-pole molded case circuit breaker rated for 250 A continuous current, built for line protection in distribution panels. It carries an ETU320 electronic trip unit with a shunt trip (STL) for remote opening, plus 2 auxiliary switches and 1 trip alarm switch (HQ) for status feedback to a PLC or annunciator. Breaking capacity runs 242 kA at 240 V, 187 kA at 415 V and 440 V, 121 kA at 500 V, and 40 kA at 690 V — enough headroom for high-fault utility feeds or transformer secondaries without cascading upstream. Rated insulation voltage is 800 V, so it's comfortable on 690 V systems with margin for transient spikes.
Current derating and thermal limits
Full 250 A rating holds through 50 °C ambient; above that it derates stepwise: 240 A at 55 °C, 235 A at 60 °C, 230 A at 65 °C, 225 A at 70 °C. If the panel ambient runs hot, size the feeder and buswork for the derated figure, not the nameplate. Maximum power loss is 37.5 W — modest for a 250 A frame, but cluster several breakers in a sealed enclosure and the heat adds up. Account for it in the thermal design.
Lifecycle and sourcing posture
For a critical-spare holding or a BOM freeze, this is the one to put in the cabinet before it fails. No substitute needed; the 3VA2325-6HL32-0HH0 is the active build.
Dimensions and panel fit
The breaker measures 110 mm deep, 138 mm wide, and 248 mm tall. That's a standard 3-pole MCCB footprint for the SENTRON 3VA frame — mounts on a mounting plate or DIN rail adapter, with busbar or cable connections on the line and load sides.
Trip unit and auxiliary options
The ETU320 electronic trip unit provides adjustable overload and short-circuit protection with a trip indicator and voltage trigger capability. No undervoltage release, no ground-fault monitoring, no communication module — this is a straightforward line-protection breaker with a shunt trip for remote disconnect. The integrated auxiliary trip (shunt release) is order code 3VA9688-0BL30; the supplied basic switch is 3VA2325-6HL32-0AA0. Both are factory-installed, not field-retrofit items.