What it is and what the ratings mean
The Siemens SENTRON 3VA2225-5KQ42-0AA0 is a 4-pole molded case circuit breaker (MCCB) rated for line protection, carrying a continuous uninterrupted current Iu of 250 A and an insulation voltage of 800 V. The headline number here is the breaking capacity: 187 kA at 240 V AC, 121 kA at 415 V and 440 V, 75.6 kA at 500 V, and 4.5 kA at 690 V. That means it can safely interrupt fault currents up to those levels at the respective voltages — critical for high-available-fault-current installations like large transformer secondaries or industrial mains. The ETU860 electronic trip unit gives you adjustable long-time, short-time, instantaneous, and ground-fault protection curves, plus a communication function for remote monitoring.
Thermal derating — the real current you get
The 250 A rating holds up to 50 °C ambient. Above that, derate: 238 A at 55 °C, 225 A at 60 °C, 213 A at 65 °C, and 200 A at 70 °C. If your panel runs hot — near a drive cabinet or in a non-climate-controlled enclosure — the 60 °C or 65 °C figure is the one you size the load against, not the 40 °C number. Maximum operating temperature is 70 °C; storage range is -40 °C to 80 °C.
Panel fit and integration
Dimensions: 181 mm high, 140 mm wide, 86 mm deep. That 86 mm depth is the key number for enclosure depth clearance — it's a standard MCCB depth for this frame size, so it fits most 200 mm+ deep enclosures with room for wiring gutters. The front face carries IP40 protection; the N-conductor protection is adjustable OFF or 20% to 100%. No undervoltage release or voltage trigger on this variant, but the communication function is present.
How it compares to the 3VA2116-5HM42-0CC0
The 3VA2116-5HM42-0CC0 is a smaller-frame 3VA1 series breaker — lower current rating, different trip unit, and a 3-pole design. The 3VA2225-5KQ42-0AA0 is a 4-pole, 250 A frame with the ETU860 electronic trip; it will not drop into a panel wired for the 3VA1 without a busbar rework and likely a larger enclosure cutout. If you're replacing a 3VA1 in the field, check the mounting footprint first — the 3VA2 frame is physically larger.