The Siemens SENTRON 3VA1140-3GF42-0AA0 is a 4-pole molded case circuit breaker (MCCB) rated at a continuous 40 A, designed for line protection in distribution panels. Its TM240 thermal-magnetic release provides overload and short-circuit protection without the need for an external trip unit. The 75.6 kA interrupting rating at 240 V AC gives substantial fault-current headroom for most industrial service-entrance or feeder applications — at 415 V it still clears 52.5 kA, and at 690 V it holds 11.9 kA, so the same breaker covers mixed-voltage panels without a derating surprise.
Ratings and thermal performance
The 40 A rating holds flat from 40 °C up to 50 °C ambient — no derating needed in a warm enclosure. At 55 °C it drops one amp to 39 A, and by 70 °C it's at 37 A. That thermal curve means a panel builder can load this breaker to its full 40 A in a standard 40 °C environment without over-specifying. The rated insulation voltage is 800 V, so it's comfortable in 480 V and 600 V class systems with margin. Power loss at rated load is 10.8 W — modest for a 4-pole frame, but worth accounting for in a densely packed enclosure.
Physical fit and panel integration
The 3VA1140-3GF42-0AA0 occupies a 101.6 mm wide, 130 mm tall, 70 mm deep footprint — a standard 4-pole MCCB frame that fits most DIN-rail or panel-mount enclosures without surprise. Front face is IP40 rated, so it's protected against tools and solid objects larger than 1 mm; the rest of the breaker body is open to the enclosure for heat dissipation. No undervoltage release, no shunt trip, no communication module on this variant — it's a straight thermal-magnetic line-protection breaker with no auxiliary electronics to fail.