Siemens SENTRON 3VA2225-7HM42-0AA0 — 4-pole MCCB, 250 A frame, line protection
The Siemens 3VA2225-7HM42-0AA0 is a SENTRON molded case circuit breaker (MCCB) designed for line protection in distribution panels. It carries a 250 A continuous current rating and a trip range from 50 A to 2500 A, meaning the adjustable thermal-magnetic or electronic trip unit can be set anywhere within that window to match the downstream load without swapping the breaker frame. Four poles handle three-phase plus neutral switching, with an 800 V rated insulation voltage (Ui) that covers 400 V and 690 V systems comfortably. The interrupting ratings are the headline here: 330 kA at 240 V, 242 kA at 415 V and 440 V, 187 kA at 500 V, and 4.5 kA at 690 V — these are the SCCR values the breaker can clear without failing, so on a 415 V panel this unit gives you 242 kA of fault-current headroom, enough for high-capacity transformer secondaries. Thermal derating is published across the operating range: full 250 A up to 50 °C ambient, then 241 A at 55 °C, 232 A at 60 °C, 222 A at 65 °C, and 213 A at 70 °C. If the panel ambient runs above 50 °C, the continuous current must be reduced per that curve — a common oversight during panel layout that forces a larger frame if ignored. The breaker measures 86 mm deep, 140 mm wide, and 181 mm high — a standard SENTRON 3VA2 frame footprint that fits the same panel cutout and busbar spacing as other 3VA2 250 A units. Maximum power loss is 48 W at rated current, which matters for enclosure thermal calculations when grouping multiple breakers. A ground-fault monitoring version using summation current formation on L + N conductor is built in — this detects leakage by comparing line and neutral current, tripping on imbalance. No undervoltage release, no voltage trigger, no communication function, and no trip indicator are fitted on this variant; it is a straight line-protection breaker with ground-fault sensing.
Mounting and integration
Mounts on a DIN rail or directly to a backplate via the screw terminals. The 140 mm width leaves room for adjacent breakers in a multi-pole lineup; the 86 mm depth fits standard 200 mm deep enclosures without crowding the gland plate. Busbar connectors and phase isolators are available from the SENTRON accessory family — no custom drilling needed.