What it is — and what the ratings mean for fit
The Siemens 3VA1040-4ED46-0AA0 is a SENTRON molded case circuit breaker (MCCB) for line protection, built around a 4-pole, 40 A frame with a TM210 thermal-magnetic overcurrent release. The 40 A continuous rating holds from 40 °C through 50 °C, then derates to 39 A at 55 °C and 37 A at 70 °C — so if your panel ambient runs hot, you still get full current up to 50 °C without stepping up a frame size. Breaking capacity hits 121 kA at 240 V AC, drops to 75.6 kA at 415 V, and holds at 11.9 kA all the way to 690 V AC. That 690 V rated operational voltage means it clears faults on 480 V and 600 V class systems with headroom.
Panel fit and mounting
At 101.6 mm wide, 130 mm tall, and 70 mm deep, this 4-pole MCCB fits standard SENTRON mounting feet — direct panel mount or onto a DIN rail adapter. The IP40 front means it is protected against tool entry and >1 mm particles; it expects a closed enclosure in a typical panel. Maximum power loss is 10.8 W, so factor that into your enclosure thermal budget if multiple breakers sit side by side.