What this MCCB delivers — and what the ratings mean for your panel
The Siemens SENTRON 3VA2125-6KQ42-0AA0 is a 4-pole molded case circuit breaker rated for 25 A continuous current, sized for line-protection duty with integrated ground-fault monitoring via summation current sensing on L+N conductors. Its breaking capacity is what decides the fit for your fault-current study: 242 kA at 240 V AC, 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 this breaker clears very high available fault currents typical at the service entrance or near large transformers — it is not just a feeder breaker. The 25 A rating holds flat across the full operating temperature range from -25 °C to 70 °C — no derating curve to calculate for ambient heat inside a sealed panel. Insulation voltage is rated 800 V, so the breaker is suitable for 480/277 V and 600/347 V systems with margin.
Mounting and integration into the enclosure
Dimensions are 181 mm high, 140 mm wide, 86 mm deep — a 4-pole MCCB footprint that fits standard Siemens SENTRON mounting plates and busbar systems. The 86 mm depth leaves clearance for rear-connected busbars or cable lugs in a 200 mm deep enclosure. Communication function is onboard, which for the 3VA2 platform typically means a modular communication-capable trip unit that can report status and measured values over a fieldbus gateway — useful for remote monitoring without adding an external power meter.
Lifecycle and compliance posture
For compliance documentation: the 3VA2 series carries CE marking under the Low Voltage Directive, UL 489 listing for the North American market, and RoHS/REACH declarations from Siemens. The ground-fault monitoring variant (summation current) meets the requirements of IEC 60947-2 Annex B for residual current protection.