What this MCCB is and what it does
The Siemens 3VA2140-6KQ32-0AA0 is a SENTRON molded case circuit breaker (MCCB) in the 3VA2 series, rated for line protection in distribution panels. It carries a continuous current of 40 A across the full ambient temperature range from 40 °C to 70 °C — no derating needed up to that ceiling, which simplifies panel sizing in warm enclosures. Three poles, fitted with an ETU860 electronic trip unit. The ETU860 brings adjustable long-time (tr 0.5–25 s) and short-time (tsd up to 0.5 s) response values, plus ground-fault monitoring via summation current formation on the L-conductor. That makes it suitable for feeders where selective coordination and earth-leakage detection are required — common in process plant sub-distribution.
Breaking capacity — what the numbers mean for your fault level
Rated breaking capacity is 242 kA at 240 V, 187 kA at 415 V and 440 V, 121 kA at 500 V, and 3.8 kA at 690 V. The 240 V figure is exceptionally high — it tells you this breaker is designed for high-fault-current industrial services, not just light commercial distribution. At 690 V the capacity drops sharply to 3.8 kA, so verify your system's prospective fault current at that voltage before specifying.
Panel fit and environmental limits
Dimensions: 181 mm high, 105 mm wide, 86 mm deep. The 105 mm width is standard for a 3-pole MCCB in this class — it fits the usual DIN-rail or mounting-plate footprint without surprises. Front protection is IP40, so it's protected against tools and small solids but not washdown; keep it inside a sealed enclosure if the panel sees hose spray or condensation. Operating temperature range spans -40 °C to 70 °C, with storage from -40 °C to 80 °C. That covers most indoor industrial environments, including unheated electrical rooms in cold climates. Maximum power loss is 1.6 W — negligible for thermal budgeting inside a panel.