What it is and what the ratings mean
The Siemens 3VA1140-4EF32-0JH0 is a SENTRON molded case circuit breaker (MCCB) built for line protection — the main disconnect or feeder breaker in a distribution panel. It's a 3-pole unit rated 40 A continuous at 40 °C, and it holds that rating all the way to 50 °C before it starts to derate: 39 A at 55 °C, 38 A at 65 °C, 37 A at 70 °C. That thermal stability means you don't lose headroom in a warm enclosure. The interrupting rating is where this breaker earns its keep: 121 kA at 240 V, 75.6 kA at 415 V, 52.5 kA at 440 V, and still 11.9 kA at 690 V. That's a high-fault-current design — sized for a main breaker position where the utility transformer can dump serious energy into a bolted fault. The 800 V rated insulation voltage confirms it's rated for 690 V industrial systems.
Auxiliary and shunt trip configuration
This variant ships with a factory-installed shunt trip (STL) and an auxiliary switch block: 2 auxiliary switches plus 1 trip alarm switch HQ. That's the '4EF32' part of the order code — the shunt trip lets a remote signal (emergency stop, fire alarm, PLC interlock) open the breaker without anyone pulling the handle. The trip alarm switch closes when the breaker trips on fault, so a panel PLC or annunciator sees the event. No undervoltage release on this unit, and no ground-fault monitoring module. If you need UVR or GF protection, you'd step to a different suffix in the 3VA family. The auxiliary switches are wired via the standard SENTRON terminal block — same footprint as the base breaker.
Physical fit and environment
Dimensions: 70 mm deep, 76.2 mm wide, 130 mm tall. That's a standard SENTRON 3VA1 frame size — it mounts on a DIN rail or screws into a panel backplate with the same hole pattern as other 3VA1 breakers. Operating temperature range is -25 °C to 70 °C; storage from -40 °C to 80 °C. The power loss at full load is 10.8 W — modest enough that you don't need forced cooling in a typical enclosure.