The Siemens SENTRON 3VA1140-4EE36-0AF0 is a 3-pole molded case circuit breaker (MCCB) rated for 40 A continuous current at 40 °C ambient, with a TM220 thermal-magnetic trip unit designed for line protection. At 240 V the interrupting rating climbs to 121 kA, which covers most North American panelboard applications.
Thermal derating and operating envelope
The 40 A rating holds flat from 40 °C to 50 °C, then drops to 39 A at 55 °C and 37 A at 70 °C. That derating curve matters when the breaker is packed into a warm enclosure alongside other heat sources — the 70 °C figure is the operating maximum, not a storage limit.
Physical integration and auxiliary switch configuration
The breaker occupies 76.2 mm width, 130 mm height, and 70 mm depth — a 3-inch wide footprint that fits standard Siemens SENTRON panelboard cutouts and DIN-rail adapter plates. No undervoltage release or communication module is fitted from the factory.
The interrupting rating varies significantly with system voltage: 121 kA at 240 V, 75.6 kA at 415 V, 52.5 kA at 440 V, and 11.9 kA at both 500 V and 690 V. The drop above 500 V is steep — this is not a 690 V-optimized breaker.