What the ratings mean for fit
The Siemens SENTRON 3VA2340-5HL42-0CL0 is a 4-pole molded case circuit breaker rated for 400 A continuous current at 40 °C, with a maximum breaking capacity of 187 kA at 240 V. That 187 kA figure at 240 V tells you this breaker handles high-fault scenarios typical in industrial distribution — it safely interrupts faults up to that level without cascading upstream. At 415 V and 440 V the breaking capacity holds at 121 kA, dropping to 75.6 kA at 500 V and 7.5 kA at 690 V, so the voltage class of your system determines which rating governs the installation. The continuous current derates from 400 A at 50 °C down to 340 A at 70 °C, meaning the breaker must be sized for the actual ambient temperature in the enclosure, not just the nameplate 400 A. This is a line-protection design (not motor or generator protection), so it's intended for feeder circuits in switchboards and panelboards where the primary need is overcurrent and short-circuit protection of cables and busbars. The 4-pole configuration suits three-phase systems with a fully rated neutral — common in North American 120/208 V and 277/480 V wye services, or European TN systems where the neutral is switched.
Built-in auxiliaries and releases
The breaker ships with an undervoltage release (UVR) and a complement of auxiliary switches: 2 auxiliary switches + 1 trip alarm switch + 1 electrical alarm switch HQ. That's enough for remote status indication — the trip alarm signals a fault condition, the electrical alarm switch provides a separate signal for the breaker's on/off state, and the two auxiliary switches can be wired into a PLC or SCADA for position feedback. The UVR automatically trips the breaker when control voltage drops below a threshold, which is standard for emergency-stop circuits or undervoltage protection schemes. The basic switch assembly is order code 3VA2340-5HL42-0AA0, meaning the -0CL0 suffix adds the UVR and the specific auxiliary switch configuration. If you're replacing a failed unit, verify the aux switch count matches your existing wiring — the 2+1+1 layout is more than the bare minimum and may require additional terminal space in the panel.
Lifecycle and sourcing reality
For a BOM line, the key fit confirmations are the 400 A continuous rating (verify your load doesn't exceed the derated value at your enclosure ambient), the 4-pole configuration, and the breaking capacity at your system voltage. The 187 kA at 240 V covers most North American low-voltage distribution, while the 121 kA at 415 V suits European 400 V systems. If you're working at 690 V, the 7.5 kA breaking capacity is a significant drop — verify your fault current doesn't exceed that.
Physical integration
Dimensions are 248 mm high, 184 mm wide, 110 mm deep. That 110 mm depth is shallow enough for most standard distribution enclosures — it won't force a deeper can than the panel builder planned. The 184 mm width for a 4-pole breaker is typical for the 400 A frame size; verify the mounting footprint matches your existing busbar or lug kit spacing before committing the panel layout. Maximum power loss is 98.5 W at rated current. That's the heat the breaker dissipates into the enclosure — factor it into your thermal budget, especially if the panel is densely packed or installed in a high-ambient environment. The operating temperature range is -25 °C to 70 °C, with storage from -40 °C to 80 °C.