What it is and what it does
The Siemens SENTRON 3VA2340-7HL32-0BH0 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. Its interrupting capacity reaches 330 kA at 240 V and 242 kA at 415 V — the 330 kA figure at 240 V covers high-fault utility feeds where a standard MCCB would cascade failure upstream. At 690 V the rating drops to 7.5 kA, so this breaker is sized for low-voltage mains, not 690 V motor circuits.
Ratings that decide the fit
The adjustable thermal-magnetic trip range spans 600 A to 4 000 A — that's the long-time and short-time pickup window, not the frame rating. The 400 A continuous current holds flat from 40 °C through 50 °C, then derates linearly: 385 A at 55 °C, 370 A at 60 °C, 355 A at 65 °C, 340 A at 70 °C. In a 65 °C non-vented enclosure you lose 45 A off the nameplate; factor that into the load calculation. Maximum power loss is 98.5 W — that's the heat the breaker dumps into the enclosure at full rated current. For a panel with multiple breakers side by side, that figure drives the ventilation or derating stack-up.
Built-in auxiliaries and releases
This variant ships with an undervoltage release (UVR) and a 2 auxiliary switch + 1 trip alarm switch HQ configuration. The UVR drops the breaker when control voltage falls below the dropout threshold — standard for emergency-stop chains or undervoltage protection schemes. The trip alarm switch gives a positive signal when the breaker trips on fault, separate from the aux switches that track the main contact position. The basic switch assembly is order code 3VA2340-7HL32-0AA0, meaning the UVR and aux switch block are integrated at the factory, not field-added. No communication function and no ground-fault monitoring on this version — it's a straight thermal-magnetic line-protection breaker with undervoltage release.
Lifecycle and sourcing reality
For a BOM line or a replacement order, the fit is confirmed by the 400 A continuous rating, 3-pole form factor, and the integrated UVR + aux switch complement. Sourced and quoted to order against an RFQ through independent distribution — availability and current pricing confirmed at quote time.
Physical footprint and environmental limits
Dimensions are 248 mm height, 138 mm width, 110 mm depth — the 110 mm depth (4.33 in) is the panel depth needed behind the mounting surface, not including the handle projection. Operating temperature range is -25 °C to 70 °C; storage range is -40 °C to 80 °C. The storage minimum of -40 °C matters for unheated warehouses or cold shipping — the breaker will function after a deep freeze, but the UVR coil should be verified for condensation before energizing. A trip indicator is present — a mechanical flag visible on the breaker face that shows tripped vs. on/off status without needing to read the handle position.