What this MCCB is and what the ratings mean for fit
The Siemens 3VA2025-6KQ42-0AA0 is a SENTRON molded case circuit breaker (MCCB) designed for line protection in distribution panels. Its continuous rated current of 25 A holds steady across the full operating temperature range from -25 °C to 70 °C (, –) — no derating curve to chase when the panel runs warm. The adjustable thermal trip band of 15–25 A lets you set the overload threshold to match the downstream conductor or load, not the breaker's maximum. Breaking capacity is the headline number that decides whether this breaker clears a fault without venting or welding closed. At 240 V it interrupts 242 kA; at 415 V and 440 V it holds 187 kA; at 500 V it drops to 121 kA; at 690 V it still clears 3 kA. That 242 kA figure at 240 V is among the highest in the SENTRON 3VA2 family — it is sized for high-fault panels close to the transformer secondary, not for a branch circuit with 10 kA available. The 800 V rated insulation voltage confirms it is built for 480/277 V and 600 V nominal systems with headroom.
Ground-fault and communication — what is built in
This 4-pole MCCB includes ground-fault monitoring via summation current formation on the L + N conductor. That means it senses the vector sum of phase and neutral currents — a common method for detecting leakage to earth without a separate GFCI module. It also carries a communication function and an other measurement function, which points to an electronic trip unit capable of reporting status or values over a bus. No undervoltage release is fitted, and the trip indicator is absent — the trip state is read from the handle position or communicated electronically.
Panel fit and physical integration
The 3VA2025-6KQ42-0AA0 measures 181 mm high by 140 mm wide by 86 mm deep. That 86 mm depth is the dimension that matters for gland-plate clearance and whether the breaker fits a shallow enclosure. The 140 mm width for a 4-pole MCCB is standard for the SENTRON 3VA2 frame — it occupies the same footprint as the 3VA2125-8KQ42-0AA0, so a panel laid out for one accepts the other without drilling new mounting holes or rerouting bus bars.
Lifecycle and sourcing posture
The lifecycle stage is listed as current — this is an active-production part from Siemens, not a phase-out or NRND item. It is sourced and quoted to order against an RFQ through independent distribution, with availability and current pricing confirmed at quote time.