What this MCCB carries — and what it doesn't
The Siemens 3VA2140-7MQ36-0AA0 is a 3-pole SENTRON molded case circuit breaker (MCCB) in the motor protection version, rated for a continuous current of 40 A across the full ambient range from 40 °C to 70 °C — no derating curve to chase at the top end. It ships with the ETU860M electronic overcurrent release, which brings phase failure detection, ground fault monitoring via summation current formation on the L-conductor, and a communication function — meaning this breaker talks to the control system, not just trips in a hole. Breaking capacity is the headline number here: 330 kA at 240 V, 242 kA at 415 V and 440 V, 187 kA at 500 V, and 3.8 kA at 690 V. That 330 kA at 240 V is the figure that buys you into high-fault panels without cascading upstream — common in industrial distribution where transformer impedance is low.
DIN-rail fit and panel integration
Footprint is 105 mm wide by 181 mm tall by 86 mm deep — a standard 3-pole MCCB envelope that drops into most SENTRON distribution boards and downstream panelboards without re-drilling the gland plate. Front face carries IP40 protection — fine for a dry indoor panel; not rated for washdown or outdoor exposure. Maximum power loss is 10 W, which matters when you're stacking several breakers in a sealed enclosure — that heat has to go somewhere.
Lifecycle and sourcing reality
Lifecycle stage is marked as current — meaning Siemens still actively produces this variant, no phase-out notice on the horizon. Rated insulation voltage is 800 V, and latching endurance is rated at 20,000 operations.