What this MCCB is and where it fits
The Siemens 3VA2040-8HL36-0AA0 is a SENTRON molded case circuit breaker (MCCB) rated for 40 A continuous current across the full ambient range from 40 °C to 70 °C — no derating needed up to that ceiling. It's a 3-pole, line-protection design with an ETU320 electronic trip unit, meaning the trip curve is adjustable and the breaker is sized for feeder or main protection in a distribution panel, not for direct motor starting. The 800 V rated insulation voltage gives it headroom for 480 V and 600 V class systems without creeping clearance issues. Breaking capacity is the headline here: 440 kA at 240 V AC, 330 kA at 415 V and 440 V, 220 kA at 500 V, and still 52.5 kA at 690 V. Those are numbers that let it sit upstream of a high-fault panel without worrying about cascading failure — the breaker clears a bolted fault before the arc has time to propagate. For a 40 A frame, that's an unusual amount of interrupting muscle; it's not a branch device, it's a main or a large-feeder interrupter in a high-capacity switchboard.
Mounting and panel fit
Footprint is 105 mm wide by 181 mm tall by 86 mm deep — a standard 3-pole MCCB envelope that bolts into a panel or mounts on a mounting plate. The IP40 front protection means it's fine in a clean indoor enclosure; keep the gland plate sealed if the panel sees dust or washdown. No undervoltage release, no ground-fault monitoring, no communication module on this variant — it's a straight line-protection breaker with the ETU320 doing the sensing.