The Siemens SENTRON 3VA1140-3EF36-0AE0 is a 3-pole molded case circuit breaker (MCCB) rated for 40 A continuous at 40 °C, with a TM240 thermal-magnetic release designed for line protection. It carries an interrupting capacity of 75.6 kA at 240 V, stepping down to 52.5 kA at 415 V, 32 kA at 440 V, and 11.9 kA at 500 V or 690 V — that coverage matters when you're coordinating downstream faults and need to know the breaker can clear a bolted fault at the service voltage without welding contacts.
What the ratings mean for fit
The 40 A rating holds flat across ambient temperatures from 40 °C to 50 °C, then derates only to 39 A at 55-60 °C and 38 A at 65 °C, finally 37 A at 70 °C. That thermal stability means you don't lose headroom in a warm enclosure — the breaker stays at full rating through most panel conditions. The TM240 release is a thermal-magnetic type, so it handles both overload (thermal curve) and short-circuit (magnetic instantaneous) protection without an external trip unit. Rated insulation voltage is 800 V, which covers 480/277 V and 600 V systems with margin. Maximum power loss is 10.8 W — negligible for thermal budgeting in a crowded panel, but worth noting if you're stacking multiple breakers in a sealed sub-feed. The breaker is 130 mm high, 76.2 mm wide, and 70 mm deep — a 3-pole footprint that mounts on a DIN rail or panel-mount plate. The 70 mm depth is shallow enough to fit most standard distribution enclosures without interfering with the deadfront.
Where it fits in a panel
This is a line-protection MCCB for main or branch feeder duty in a SENTRON distribution board or standalone enclosure. The 3-pole configuration suits three-phase loads — panel feeds, motor control centers, or sub-distribution. No ground-fault monitoring and no undervoltage release on this variant, so if you need those functions you're looking at a different suffix in the 3VA family.