400 A line protection with ETU320 — what the ratings mean for panel fit
The Siemens SENTRON 3VA2440-6HL32-0CL0 is a 3-pole molded case circuit breaker rated for a continuous current Iu of 400 A, with an ETU320 electronic trip unit configured for line protection. The 242 kA breaking capacity at 240 V (187 kA at 415 V, 121 kA at 500 V, 40 kA at 690 V) gives substantial SCCR headroom for high-fault installations — the breaker clears faults up to that level without cascading upstream, which matters when coordinating downstream feeders in a main distribution panel. Thermal derating is published across the full operating range: the breaker carries a full 400 A up to 50 °C ambient, then steps down to 384 A at 55 °C, 376 A at 60 °C, 368 A at 65 °C, and 360 A at 70 °C. For a panel builder sizing a main breaker in a non-climate-controlled enclosure, the 55 °C column is often the real-world rating — 384 A continuous, not the nameplate 400 A. The auxiliary contact complement is 2 auxiliary switches + 1 trip alarm switch + 1 electrical alarm switch HQ, which provides status feedback for PLC-based monitoring without adding external relays. The integrated undervoltage release (UVR) allows a safety circuit to trip the breaker on loss of control voltage — a common requirement for emergency-stop chains and power-management systems.
Lifecycle and sourcing — current production, quoted to order
The 3VA2440-6HL32-0CL0 carries the SENTRON branding and is designed to IEC 60947-2 and UL 489 standards. The ETU320 trip unit is field-configurable for LSI protection curves, which gives the specifying engineer flexibility to adjust long-time, short-time, and instantaneous pickup thresholds without swapping hardware.
Panel integration — footprint and mounting
Dimensions are 248 mm height × 138 mm width × 110 mm depth. The 138 mm width fits a standard 3-pole MCCB cutout in a distribution board. Maximum power loss is 66 W, which should be factored into the enclosure thermal budget — particularly when multiple breakers are ganged in a sealed cabinet. Operating temperature range is -25 °C to 70 °C, with storage from -40 °C to 80 °C. The storage range exceeds the operating range — that limit governs handling and warehousing, not running conditions. The part is not conformally coated as standard, so for marine or high-humidity environments, verify the enclosure rating separately.