What this MCCB is and what it does
The Siemens SENTRON 3VA2340-7HL32-0CH0 is a 3-pole molded case circuit breaker (MCCB) rated for 400 A continuous current at 40 °C, designed for line protection in distribution panels and switchboards. Its 330 kA breaking capacity at 240 V means it can safely interrupt very high fault currents without upstream cascading — critical for high-available-fault installations like large transformer secondaries or industrial service entrances.
Key ratings and what they mean for fit
The 400 A continuous rating holds across 40 °C to 50 °C ambient without derating; at 55 °C it derates to 385 A, at 60 °C to 370 A, at 65 °C to 355 A, and at 70 °C to 340 A. For a panel running warm near the top of a switchboard, this thermal curve tells you whether the breaker stays within its rated ampacity without a larger frame. Breaking capacity steps down with voltage: 330 kA at 240 V, 242 kA at 415 V and 440 V, 187 kA at 500 V, and 7.5 kA at 690 V. The steep drop at 690 V means this breaker is not a primary choice for 690 V systems unless the available fault current is well under 7.5 kA — verify the point-of-installation SCCR before specifying. Dimensions are 248 mm high, 138 mm wide, 110 mm deep — a standard 3-pole MCCB footprint that fits most SENTRON mounting plates and panel cutouts. The 110 mm depth leaves clearance for rear-connected busbars or cable ladders behind the breaker.
Built-in accessories and wiring
This variant ships with an undervoltage release (UVR) and two auxiliary switches plus one trip alarm switch (HQ). The UVR trips the breaker when control voltage drops below a threshold — standard for emergency-stop or undervoltage protection schemes. The auxiliary switches provide status feedback to a PLC or indication lamp; the trip alarm switch signals a fault trip separately from a manual open. The basic switch is order code 3VA2340-7HL32-0AA0, meaning the accessory set is factory-integrated rather than field-added. A trip indicator is present for visual fault confirmation. No ground-fault monitoring or communication module is included on this variant.