What it is and what the ratings mean
The SENTRON 3VA2125-6JQ36-0AA0 is a 3-pole molded case circuit breaker (MCCB) rated for 25 A continuous current, designed for line protection in distribution panels. Its breaking capacity is 242 kA at 240 V AC, dropping to 187 kA at 415 V and 440 V, 121 kA at 500 V, and 3.7 kA at 690 V — that 242 kA figure at 240 V means it can safely interrupt a fault of that magnitude without upstream fuses needing to clear, which is useful for high-fault service entrances or transformer secondaries. The 25 A rating holds steady across the full ambient range from 40 °C to 70 °C, so no derating needed in a warm enclosure. Rated insulation voltage is 800 V, and the breaker includes a communication function and ground-fault monitoring via summation current formation on the L-conductor. That communication function means it can report status or trip events to a BMS or PLC — useful for remote monitoring on a critical feeder. Power loss is 0.6 W maximum, negligible for panel heat budget.
Panel fit and integration
Dimensions are 105 mm wide, 181 mm tall, 86 mm deep — standard MCCB footprint for a 3-pole 25 A unit. Mounts on DIN rail or direct panel; the 86 mm depth leaves clearance for wiring and bus connections in a typical distribution cabinet. The 0.6 W dissipation means no forced cooling needed even in a sealed enclosure.