Siemens SENTRON 3VA2340-7HL42-0AA0 — 400 A Molded Case Circuit Breaker, Line Protection
The Siemens SENTRON 3VA2340-7HL42-0AA0 is a 4-pole molded case circuit breaker (MCCB) rated for line protection, with a continuous current Iu of 400 A and an interrupting capacity of 330 kA at 240 V. The interrupting rating drops to 242 kA at 415 V and 440 V, 187 kA at 500 V, and 7.5 kA at 690 V — figures that define the available fault current the breaker can safely clear at each voltage level, critical for selectivity coordination studies. The ETU320 electronic trip unit provides adjustable long-time pickup and delay (tr min. 0.5 s, tr max. 17 s) and configurable N-conductor protection (OFF, 50%, 100%). The breaker is rated for an insulation voltage Ui of 800 V and operates over an ambient range of -25 °C to 70 °C, with a maximum power loss of 96 W.
Current Rating and Thermal Derating
The breaker carries its full 400 A rating up to 50 °C ambient. Above that, derating applies: 385 A at 55 °C, 370 A at 60 °C, 355 A at 65 °C, and 340 A at 70 °C. For panel builders, this means the MCCB can be installed in a 50 °C enclosure without downsizing the frame; above that, the load current must be reduced or ventilation added.
Physical Dimensions and Panel Fit
Dimensions: 248 mm high, 184 mm wide, 110 mm deep. The 4-pole width (184 mm) is the key panel-space constraint — verify that the DIN-rail or mounting-plate allocation matches this footprint. The IP40 front protection allows use in enclosed switchgear; no washdown rating.