Siemens 3VA1140-6EF32-0AC0 — SENTRON Molded Case Circuit Breaker, 40 A, Line Protection
The Siemens 3VA1140-6EF32-0AC0 is a 3-pole SENTRON molded case circuit breaker (MCCB) rated at 40 A continuous current, designed specifically for line protection in distribution panels. It carries a TM240 thermal-magnetic overcurrent release — the '240' denotes the frame size, not the trip rating, so the 40 A continuous rating is the figure that governs your load sizing. Breaking capacity is 220 kA at 240 V, 154 kA at 415 V, and 121 kA at 440 V, dropping to 17 kA at 500 V and 690 V — the high interrupt ratings at lower voltages make this breaker suitable for high-fault-capacity service entrances or industrial sub-distribution where fault currents can exceed 100 kA.
Current Derating and Thermal Performance
The 40 A rating holds flat from 40 °C through 50 °C ambient. At 55 °C it derates to 39 A, at 65 °C to 38 A, and at 70 °C to 37 A — a 7.5 % loss from the nameplate at the top of the operating range. The operating ambient range is -25 °C to +70 °C, with storage from -40 °C to +80 °C. Maximum power dissipation is 10.8 W, which matters for thermal coordination inside a sealed enclosure. The rated insulation voltage is 800 V, giving headroom for 690 V systems.
Panel Fit and Auxiliary Switching
Dimensions are 76.2 mm wide (3 in), 130 mm high (5.12 in), and 70 mm deep (2.76 in) — a standard 3-pole MCCB footprint that drops into most SENTRON panelboards and distribution blocks without re-drilling. The breaker ships with two factory-installed auxiliary switches (HQ type), providing status feedback for remote monitoring or PLC inputs. No undervoltage release, no ground-fault monitoring, and no communication module on this variant — it is a straight line-protection device with basic auxiliary contacts.