What it is and what it does
The Siemens 3VA1140-3GE46-0AA0 is a SENTRON molded case circuit breaker (MCCB) rated for line protection. It carries a continuous current Iu of 40 A across four poles, with a TM220 thermal-magnetic release. The interrupting capacity scales with system voltage: 75.6 kA at 240 V, 52.5 kA at 415 V, 32 kA at 440 V, and 11.9 kA at 500 V or 690 V — so at 415 V it clears a 52.5 kA fault without cascading upstream, which is the figure most panel builders check for industrial distribution.
Thermal derating and panel fit
The 40 A rating holds at 45 °C and 50 °C, then derates to 39 A at 55 °C and 60 °C, 38 A at 65 °C, and 37 A at 70 °C. If the panel ambient runs above 50 °C, plan for the reduced continuous current. The enclosure footprint is 130 mm high, 101.6 mm wide, and 70 mm deep — a 4-inch-wide body that fits standard 600 mm-wide distribution boards with room for side-by-side mounting. Front IP40 means it is protected against tools and wires >1 mm, but not against water ingress; keep it inside a sealed enclosure in washdown areas.
What the ratings mean for fit
The TM220 release is a fixed thermal plus adjustable magnetic trip — the li max of 400 A sets the instantaneous pickup ceiling. For DC circuits, the maximum rated operational voltage is 600 V DC, so it can serve as a DC feeder breaker in battery or UPS applications. The 100% N-conductor protection means the neutral pole is fully rated, not reduced — required for four-wire systems where neutral loading is not negligible. Power loss at rated current is 10.8 W, modest enough that ventilation in a standard enclosure handles it without forced airflow.