What this MCCB carries — and where it fits
The Siemens 3VA2125-6KQ46-0AA0 is a SENTRON 4-pole molded case circuit breaker (MCCB) rated for line protection, with a continuous current of 25 A and a full-scale value of 25 A. Its breaking capacity hits 242 kA at 240 V and 187 kA at 415 V and 440 V — figures that put it in the high-interrupting class for industrial distribution panels where fault currents are serious. The 4-pole configuration handles three-phase-plus-neutral or dual-fed setups common in North American and European switchboards. What that 242 kA at 240 V means in practice: this breaker can safely interrupt a fault current up to 242,000 A without welding contacts or venting plasma into the enclosure. For a 25 A frame, that's enormous headroom — it's sized for the fault level at the service entrance or a large sub-distribution board, not for a downstream branch. The 3.7 kA rating at 690 V tells you the arc extinction gets harder at higher voltage, but that's still adequate for most 690 V industrial loads. The unit includes communication functionality and ground-fault monitoring via summation current formation on L + N conductors — meaning it can talk to a building management system or PLC and report trip events and leakage without a separate GFCI module. Insulation voltage is rated at 800 V, so it's comfortable in 480/277 V and 600 V panels with margin.
Panel fit and thermal derating
Footprint is 86 mm deep by 140 mm wide by 181 mm tall — a standard MCCB form factor that bolts into most Siemens SENTRON panelboards or onto a mounting plate. The depth (86 mm) is shallow enough to clear a 200 mm deep enclosure with room for wiring gutters. No undervoltage release or voltage trip trigger on this variant, so it's a straight thermal-magnetic or electronic trip unit — no auxiliary coil to wire. Thermal performance is flat across the board: rated current holds at 25 A from 40 °C all the way up to 70 °C ambient. That means no derating curve to calculate for warm enclosures — the breaker is already calibrated for a hot panel. Storage range spans -40 °C to 80 °C, which covers unheated warehouses and shipping containers.