The Siemens 3VA2225-6KP42-0HG0 is a SENTRON molded case circuit breaker (MCCB) rated for 250 A continuous current (Iu) across a 4-pole frame. It carries an ETU850 electronic trip unit, which gives adjustable long-time, short-time, instantaneous, and ground-fault protection curves — suitable for feeder or main breaker duty in LV distribution panels. Breaking capacity reaches 242 kA at 240 V, 187 kA at 415 V, and 4.5 kA at 690 V (cites:,).
Current derating and thermal limits
The breaker holds its full 250 A rating from 40 °C through 50 °C ambient. At 55 °C it derates to 240.625 A, at 60 °C to 231.25 A, at 65 °C to 221.875 A, and at 70 °C to 212.5 A (cites:,). For a panel that runs warm — say a packed enclosure with multiple breakers — the derating curve tells you the real continuous current the breaker can carry without nuisance tripping. The maximum power loss is 55 W (cites:).
Trip unit and auxiliary options
The ETU850 electronic trip unit (cites:) supports communication functions (cites:) and other measurement functions (cites:), which means it can integrate with a BMS or energy monitoring system — not just a passive breaker. It ships with a shunt trip (STL) release (cites:) and one auxiliary switch plus one trip alarm switch (HP) (cites:). The basic switch is order code 3VA2225-6KP42-0AA0 (cites:); the integrated auxiliary trip is 3VA9688-0BL30 (cites:). A voltage trigger is present (cites:); undervoltage release is not fitted (cites:). Phase failure detection is not included (cites:).
Physical fit and environment
Dimensions are 181 mm high, 140 mm wide, 107 mm deep (cites:,). Front protection is IP40 (cites:) — suitable for a dry indoor panel; not rated for washdown. Operating temperature range is -25 °C to 70 °C (cites:,); storage range is -40 °C to 80 °C (cites:,). The reference code per DIN EN 81346-2 is Q (cites:).