What this MCCB is and what it does
The SENTRON 3VM1140-3GD42-0AA0 is a 4-pole molded case circuit breaker (MCCB) rated for 40 A continuous current, built for line protection in distribution panels and motor branch circuits. Its interrupting capacity hits 76 kA at 240 V AC and still holds 53 kA at 415 V, 32 kA at 440 V, and 11.9 kA at 500 V — numbers that tell you it can clear high-fault bolted faults without cascading upstream, which is the deciding factor for panel SCCR compliance (IEC 60947-2).
Thermal derating and real-world current
The breaker holds its full 40 A rating from 40 °C up to 50 °C, then drops to 39 A at 55 °C and 60 °C, 38 A at 65 °C, and 37 A at 70 °C. That derating curve is what you need when the panel runs hot — if your enclosure ambient sits at 60 °C, you're limited to 39 A continuous, not the nameplate 40 A. The TM210 thermal-magnetic release (adjustable Ir up to 40 A) lets you fine-tune the trip point to the actual load without swapping the breaker.
Mounting and panel fit
The breaker measures 101.6 mm wide, 130 mm tall, and 70 mm deep — a standard 4-pole MCCB footprint that fits most DIN-rail or screw-mount panel layouts. IP40 on the front means it's protected against solid objects over 1 mm (tools, wires) but not sealed against moisture; install inside a rated enclosure for wet or dusty environments.
Electrical ratings and approvals context
Rated insulation voltage Ui is 690 V, and max operational voltage for DC applications is 500 V — so it can serve DC bus or battery circuits within that limit. The 12 000-cycle mechanical endurance is typical for a panel-mounted MCCB; it's not a switching contactor, but it will handle routine isolation without issue. Power loss maxes at 10.8 W, which matters for thermal budgeting inside a sealed enclosure.