Rating and trip-unit profile
The Siemens 3VA2440-5HN42-0KJ0 is a SENTRON molded case circuit breaker (MCCB) configured for line protection, carrying a rated continuous current Iu of 400 A across four poles. The ETU350 electronic trip unit provides adjustable long-time (tr) and short-time (tsd) delay settings — tr from 0.5 to 17, tsd from 0.02 s to 0.4 s — letting you shape the trip curve to the load without swapping the breaker. Neutral protection is configurable as OFF, 50 %, or 100 % of the phase setting. Breaking capacity is voltage-dependent: 187 kA at 240 V, 121 kA at 415 V, 55 kA at 440 V, 36 kA at 500 V, and 9 kA at 690 V. At 400 A continuous, the 415 V figure (121 kA) is the one that governs most industrial panel applications — it tells you this breaker can safely interrupt a fault up to that current without upstream damage, per IEC 60947-2. Current rating holds flat at 400 A from 40 °C through 50 °C ambient, then derates to 384 A at 55 °C, 372 A at 60 °C, 356 A at 65 °C, and 340 A at 70 °C. If the panel ambient runs above 50 °C, the effective continuous current drops — factor that into the load calculation.
Physical fit and panel integration
Footprint is 184 mm wide by 248 mm tall by 110 mm deep. The 184 mm width (7.2 in) is the critical dimension for DIN-rail or panel-mount spacing — it occupies roughly four 45 mm pole positions. Front IP40 protection means the breaker face is sealed against tools and fingers but not washdown; mount it inside a rated enclosure if the environment is wet or dusty. Rated insulation voltage Ui is 800 V, and the operating temperature range spans -25 °C to 70 °C, with storage from -40 °C to 80 °C. Maximum power loss at rated current is 63.3 W — that heat stays inside the panel, so verify the enclosure's dissipation capacity when grouping multiple breakers.