What this MCCB is and what it does for your panel
The Siemens SENTRON 3VA2140-7MS36-0AA0 is a 3-pole molded case circuit breaker (MCCB) rated for 40 A continuous current, with an insulation voltage of 800 V. It uses the ETU310M electronic overcurrent release, designed specifically for starter protection — meaning it coordinates with motor contactors and overload relays to clear faults quickly while riding through inrush. The interrupting ratings climb to 330 kA at 240 V and hold 242 kA at 415 V and 440 V, dropping to 187 kA at 500 V and 3.7 kA at 690 V. That 330 kA at 240 V tells you this breaker handles high available fault current without cascading upstream — a key spec for service-entrance or sub-feed applications where the transformer is close.
Thermal performance — flat derating up to 70 °C
The 40 A rating holds flat from 40 °C all the way to 70 °C ambient. That means no derating curve to calculate for typical panel environments; the breaker delivers its full nameplate current even in a hot enclosure near a drive or transformer. Operating range is -25 °C to 70 °C, storage from -40 °C to 80 °C. Maximum power loss at rated load is 1.6 W — negligible for panel thermal budgeting.
Dimensions and panel fit
Footprint is 105 mm wide, 181 mm tall, 86 mm deep. The 105 mm width is the standard 3-pole MCCB pitch for SENTRON 3VA breakers — it fits the same mounting base and busbar system as other 3VA frames, so a panel laid out for a 160 A or 250 A 3VA will accept this 40 A unit without re-drilling. Depth of 86 mm leaves clearance behind the panel door for wiring and accessory modules.