The Siemens SENTRON 3VA2440-7MQ32-0KK0 is a 3-pole molded case circuit breaker (MCCB) rated for 400 A continuous current at 40 °C through 70 °C — no derating needed across that entire ambient span, which is unusual and simplifies panel thermal budgeting. It carries a 330 kA interrupting rating at 240 V, 242 kA at 415 V and 440 V, and 187 kA at 500 V; at 690 V it still holds 9 kA. The motor protection variant uses an ETU860M electronic trip unit with phase failure detection and communication capability, so it can talk to a higher-level control system for load monitoring and fault annunciation.
The 400 A continuous rating at 70 °C means this breaker handles full load in a hot enclosure without forced cooling — a real advantage in a packed panel or near a motor. The ETU860M release is adjustable: response time tr from 3 s to 25 s, and tsd from 0 s up, giving the commissioning engineer fine control over coordination with downstream devices. Latching endurance of 15,000 cycles covers the mechanical life for frequent switching applications like motor feeders in a conveyor line.
Panel integration
The 138 mm width matches the common 3-pole frame spacing; verify gland plate cutout and busbar spacing before committing the panel layout. The IP40 front allows the breaker to be mounted with the front accessible through a panel door; no additional sealing is required for indoor use.