What this MCCB is and what it protects
The Siemens SENTRON 3VA2125-6HM32-0AA0 is a 3-pole molded case circuit breaker (MCCB) rated for 25 A continuous current, designed specifically for line protection — meaning it guards feeder cables and distribution buswork against overloads and short circuits, not motor or branch-circuit loads with high inrush. Its rated insulation voltage of 800 V gives headroom for 690 V systems, and the breaking capacity climbs to 242 kA at 240 V AC — enough to clear a high-fault utility feed without cascading upstream.
Breaking capacity: what the numbers mean at your system voltage
The 242 kA at 240 V is the maximum short-circuit current this MCCB can safely interrupt at that voltage. At 415 V and 440 V it still holds 187 kA; at 500 V it drops to 121 kA. The sharp fall to 3.7 kA at 690 V means this breaker is not intended for primary 690 V distribution — that figure governs the required upstream SCCR for a 690 V panel.
Ground-fault monitoring and trip characteristics
This variant includes ground-fault monitoring via summation current formation on the L-conductor, so it detects leakage to earth without a separate GFCI module. The trip indicator is absent (no mechanical flag), and there is no undervoltage release or communication function — it is a pure thermal-magnetic breaker with ground-fault sensing. The continuous current rating holds flat at 25 A across the entire operating temperature range from -25 °C to 70 °C — no derating needed for elevated ambient temperatures up to 70 °C.
Panel fit and dimensions
At 105 mm wide, 181 mm tall, and 86 mm deep, this 3-pole MCCB fits standard SENTRON mounting bases and DIN-rail adapters. The 86 mm depth (3.39 in) is the critical dimension for enclosure depth selection — verify the door clearance if a rotary handle or extended shaft is planned.