What this MCCB is and what it does
The Siemens SENTRON 3VA2025-6KQ36-0AA0 is a 3-pole molded case circuit breaker (MCCB) designed for line protection in distribution panels. It carries a continuous current rating of 25 A and is rated for an insulation voltage of 800 V, so it handles standard 400/480 VAC industrial feeds with headroom. The interrupting capacity hits 242 kA at 240 V and 187 kA at 415 V — that SCCR lets it ride through high-fault scenarios without cascading upstream breakers.
Breaking capacity and selectivity
At 415 V this MCCB clears 187 kA, and at 500 V it still handles 121 kA. Those numbers mean the breaker can be used in high-capacity switchboards where fault current runs high — think large motor control centers or transformer secondaries. The 690 V rating drops to 3 kA, so it's not the right choice for 690 V systems with high fault potential; that's a selectivity coordination call the panel designer has to make.
Panel fit and integration
The breaker measures 105 mm wide, 181 mm tall, and 86 mm deep — a standard SENTRON 3VA footprint that drops into a DIN-rail or screw-mounted enclosure without panel modifications. The communication function (onboard) and ground-fault monitoring (summation current formation on the L-conductor) are built in, so no add-on modules eat up space in the cabinet.
Temperature derating and power loss
The 25 A rating holds flat from 40 °C all the way to 70 °C — no derating curve to calculate for warm enclosures. Maximum power loss is 0.84 W, negligible for thermal budgeting in a dense panel. Storage range is -40 °C to 80 °C, so it ships and sits fine in unheated warehouses.