What this MCCB is and what it does
The Siemens SENTRON 3VA2325-6HN32-0CL0 is a 3-pole molded case circuit breaker rated for 250 A continuous current at 40 °C, with a maximum breaking capacity of 242 kA at 240 V and 187 kA at 415 V. It's designed for line protection — meaning it sits at the incoming feed to protect downstream distribution against short circuits and overloads. The built-in undervoltage release (UVR) trips the breaker if supply voltage drops below a set threshold, which is standard for motor feeder protection or emergency-stop circuits where loss of control voltage must open the main contacts.
Breaking capacity — what the numbers mean for your panel
The 242 kA at 240 V and 187 kA at 415 V are the maximum prospective short-circuit currents this breaker can safely interrupt without welding contacts or rupturing the case. For a 250 A frame, those are high-end ratings — you'd see these in heavy industrial switchboards with large transformer feeds or motor control centers where fault currents can exceed 100 kA. At 690 V the rating drops to 7.5 kA, so if you're feeding a 690 V drive or transformer, the available fault current at that voltage must stay under that limit.
Thermal derating and continuous current
The breaker holds its full 250 A rating from 40 °C all the way up to 70 °C — no derating needed across that range. That's unusual for an MCCB; most frames start dropping current above 40 °C. It means you can pack this breaker into a warm enclosure or mount it next to other heat sources without recalculating the load. Power loss at full load is 40 W, which is modest for a 250 A frame and helps keep internal temperatures down.
Auxiliary and alarm switching
This variant ships with two auxiliary switches plus a trip alarm and an electrical alarm switch (HQ type). That gives you remote status: one set for breaker open/closed, one for tripped vs healthy, and one for electrical fault. The HQ alarm switch is typically wired into a PLC input or annunciator panel so a trip event triggers an immediate alarm without waiting for a polling cycle.