What it is and what it does
The Siemens 3VA1140-4EF32-0DA0 is a SENTRON molded case circuit breaker (MCCB) designed for line protection in 3-pole, 40 A applications. It comes factory-fitted with an undervoltage release (UVR) — the designation — so it drops the load if control voltage falls below the dropout threshold, which is a common requirement for safety disconnects in conveyor or pump panels where loss of control power must kill the motor circuit. Rated insulation voltage is 800 V, and the breaker carries a TM240 thermal-magnetic overcurrent release — the 40 A frame with fixed thermal and magnetic trip settings, no adjustability. That makes it a straight replacement for a fixed-trip MCCB in a distribution board or motor control center where coordination studies have already locked in the trip curve.
Breaking capacity — what the numbers mean for your panel
The interrupting ratings span the common industrial voltages: 121 kA at 240 V AC, 75.6 kA at 415 V, 52.5 kA at 440 V, and 11.9 kA at both 500 V and 690 V. At 415 V — the standard three-phase distribution voltage in much of Europe and Asia — 75.6 kA gives you comfortable headroom above a typical 50 kA or 65 kA fault-current spec at the main switchboard. At 690 V the 11.9 kA figure is lower, but still adequate for most motor branch circuits at that voltage class where transformer impedance limits the available fault current.
Thermal derating — the real-world current
Rated current holds at 40 A from 40 °C through 50 °C ambient — no derating needed in a standard 40 °C panel. At 55 °C it drops to 39 A, at 65 °C to 38 A, and at 70 °C to 37 A. If this breaker sits next to a row of contactors or drives that push the enclosure internal temperature to 55 °C or higher, factor that 1–3 A reduction into your load calculation. The maximum operating temperature is 70 °C; storage range is -40 °C to 80 °C.
Physical fit and panel integration
Dimensions: 130 mm high, 76.2 mm wide (3 inches — standard MCCB footprint), 70 mm deep. The 3-pole width matches the common 3-inch mounting pattern for Siemens 3VA frame breakers, so it drops into an existing panel cutout or DIN-rail adapter without re-drilling. Power loss is 13.3 W maximum — negligible for thermal budgeting in a ventilated enclosure, but worth noting if the panel is sealed and densely packed.