Siemens 3VA1140-6EF32-0AF0 — SENTRON MCCB for Line Protection
The Siemens 3VA1140-6EF32-0AF0 is a SENTRON molded case circuit breaker (MCCB) designed for line protection in distribution panels. It carries a 40 A rated current at 40 °C ambient, holds that rating steady through 50 °C, and derates only to 37 A at 70 °C — useful headroom if the panel runs hot. Breaking capacity is the headline: 220 kA at 240 VAC, 154 kA at 415 VAC, 121 kA at 440 VAC, and 17 kA at 690 VAC. That 220 kA figure at 240 V means it handles high-fault scenarios near the transformer secondary without upstream fuses needing to clear first — a real selectivity advantage in a main or feeder position. The TM240 thermal-magnetic release provides fixed thermal and magnetic trip settings, no adjustment needed — set it and commission it. Rated insulation voltage is 800 V, so the breaker is comfortable on 480/277 V and 600 V systems with margin.
Fit and Integration
Three-pole construction, 70 mm deep, 76.2 mm wide, 130 mm tall. That 70 mm depth is a standard MCCB dimension — it drops into most Siemens SENTRON panelboards and switchgear cubicles without a sub-panel spacer. The width matches the 3VA platform footprint, so existing busbar and lug kits transfer if you're swapping a 3VA1110 or 3VA1112 frame. Integrated auxiliary switch: one auxiliary contact plus one trip-alarm switch (HQ design). The trip indicator is built in — no add-on module needed to signal a fault condition to a PLC or annunciator. No undervoltage release, no communication module, no ground-fault monitoring on this variant; those are separate order-code options if the spec calls for them. Maximum power loss is 10.8 W — negligible for thermal budgeting inside a sealed enclosure, but worth noting if you're packing multiple breakers into a small panel.
Environmental and Storage
Operating temperature range: -25 °C to 70 °C. Storage range: -40 °C to 80 °C. The storage minimum of -40 °C matters if this breaker sits in an unheated warehouse or ships through a cold climate — no special cold-storage handling required.