What this 3VA2 breaker is and what it does
The SENTRON 3VA2340-7HN32-0BL0 is a 3-pole molded case circuit breaker (MCCB) rated for 400 A continuous current, built for line protection in industrial distribution panels. It carries a full-rated current of 400 A all the way up to 50 °C ambient, then derates stepwise to 340 A at 70 °C — so in a hot panel you still get nearly full rating. Breaking capacity is 330 kA at 240 V, 242 kA at 415/440 V, 187 kA at 500 V, and 7.5 kA at 690 V. That 242 kA at 415 V is what you need for a high-fault utility feed in a plant main; the 690 V number drops off sharply, so this isn't your breaker for a 690 V motor branch without checking the available fault current.
Built-in auxiliaries and releases — what's inside the case
This breaker ships with a factory-fitted set of auxiliary switches: 2 auxiliary switches, 1 trip alarm switch, and 1 electrical alarm switch (HQ type). It also includes an undervoltage release (UVR). That means you get remote status and trip indication out of the box — no separate accessory ordering for basic panel feedback. The UVR will drop the breaker if control voltage is lost, which is standard for emergency-stop or undervoltage protection schemes. Power loss at full load is 98.5 W, so factor that into panel heat dissipation.
Panel fit and handling
Dimensions are 110 mm deep, 138 mm wide, 248 mm tall. That's a standard 3-pole MCCB footprint for this current class — it'll drop into most SENTRON or equivalent mounting bases without re-drilling a gland plate. The 138 mm width means it takes three adjacent 45 mm pole spaces on a DIN rail or panel-mount adapter. Trip indicator is present, and there's no voltage-trigger or communication function on this variant — it's a straight line-protection breaker with hardwired aux contacts.