Line protection MCCB with ETU550 and comms
The Siemens SENTRON 3VA2225-6JP32-0KL0 is a 3-pole molded case circuit breaker (MCCB) rated for line protection, carrying a continuous current Iu of 250 A and a rated insulation voltage Ui of 800 V. The 242 kA breaking capacity at 240 V means it can safely interrupt very high fault currents on the secondary side of a distribution transformer — typical for a main incoming breaker in a large industrial panel. The ETU550 electronic trip unit gives you adjustable long-time, short-time, instantaneous, and ground-fault protection curves, plus communication capability for integration into a power monitoring system.
Breaking capacity across voltages — what the numbers mean
This MCCB delivers 242 kA at 240 V, 187 kA at both 415 V and 440 V, 121 kA at 500 V, and 6 kA at 690 V. The steep drop at 690 V reflects the physical limits of the arc-extinction system at higher voltages — if your system runs 690 V, the available fault current must stay under 6 kA, which typically means a transformer-impedance-limited installation or a downstream breaker. For 400 V class panels (common in European industrial mains), the 187 kA rating covers virtually any installation without an upstream current-limiting fuse.
Temperature derating — the real current you can carry
The breaker carries its full 250 A from 40 °C through 50 °C. At 55 °C it derates to 238 A, at 60 °C to 225 A, at 65 °C to 213 A, and at 70 °C to 200 A. If the panel ambient runs hot — say near a row of drives or inside a non-ventilated enclosure — the 70 °C figure of 200 A is the one to size your load against. The maximum operating temperature is 70 °C; storage range is -40 °C to 80 °C.
Auxiliary contacts and releases
Factory-fitted with 2 auxiliary switches plus 1 trip alarm switch plus 1 electrical alarm switch (HQ configuration). The shunt trip release (STL) is included for remote tripping — useful for emergency-stop circuits or supervisory shutdown. The undervoltage release is not present on this variant. The basic switch assembly carries order code 3VA2225-6JP32-0AA0; the integrated auxiliary trip is 3VA9688-0BL33.
Physical fit — panel cutout and mounting
Dimensions: 105 mm wide, 181 mm tall, 86 mm deep. This is a standard 3-pole SENTRON 3VA2 frame size — mounts via four screws to a backplate or DIN-rail adapter. The 86 mm depth leaves clearance for rear-access wiring in a 200 mm deep enclosure. Power loss is 48 W maximum at rated current, so factor that into the enclosure thermal budget.