Siemens SENTRON 3VA2340-5HN42-0DL0 — 400 A MCCB with Undervoltage Release
The Siemens SENTRON 3VA2340-5HN42-0DL0 is a 4-pole molded case circuit breaker (MCCB) rated for 400 A continuous current at 40 °C, designed for line protection in industrial power distribution panels. Its interrupting capacity reaches 187 kA at 240 V AC, 121 kA at 415/440 V, and 75.6 kA at 500 V — numbers that matter for fault-current coordination downstream of a large transformer or generator. The breaker ships with an undervoltage release (UVR) as the auxiliary release, plus a complement of 2 auxiliary switches, 1 trip alarm switch, and 1 electrical alarm switch HQ — enough status feedback for a PLC or remote monitoring system without adding external relays.
Ratings and Thermal Derating
At 40 °C ambient the breaker carries 400 A without derating. That holds through 50 °C, then steps down: 385 A at 55 °C, 370 A at 60 °C, 355 A at 65 °C, and 340 A at 70 °C. If your panel runs hot — near a drive cabinet or in a non-conditioned electrical room — the 55 °C figure is the one to size against. Maximum power loss at rated current is 98.5 W, which drives ventilation needs inside the enclosure. The operating temperature range spans -25 °C to 70 °C; storage range is -40 °C to 80 °C.
Physical Fit and Panel Integration
Dimensions: 248 mm high, 184 mm wide, 110 mm deep. The 110 mm depth is the dimension that matters for shallow backpanels or retrofit into existing switchgear buckets — measure the gutter depth before ordering. The basic switch variant is 3VA2340-5HN42-0AA0; this order code adds the UVR and auxiliary switch block pre-installed, saving panel-build labor.