What it is and what it does
The Siemens SENTRON 3VM1140-3EE42-0AA0 is a 4-pole molded case circuit breaker (MCCB) with a TM220 thermal-magnetic overcurrent release, rated for line protection in distribution panels. It carries 40 A continuously at ambient temperatures up to 50 °C without derating, and only drops to 37 A at 70 °C — so you can pack it into a warm enclosure and still hold the full 40 A through most normal operating conditions.
Breaking capacity — what the numbers mean for your fault level
This MCCB interrupts 76 kA at 240 VAC, 53 kA at 415 VAC, 32 kA at 440 VAC, and 12 kA at 500 VAC. The 76 kA figure at 240 V is the headline — it handles high-fault-capacity service-entrance panels on 240 V delta or 240/120 V split-phase systems. At 415 V (common in European industrial distribution), the 53 kA rating covers most transformer-fed switchboards; the 32 kA at 440 V still gives headroom for motor control centers. The 12 kA at 500 V is the tail — fine for 480 V panels in North America where typical available fault current runs 10–25 kA, but check your utility's SCCR study if you're above that.
Physical fit and panel integration
The 3VM1140-3EE42-0AA0 measures 130 mm high, 101.6 mm wide, and 70 mm deep. The 101.6 mm width (4 inches) is the standard 4-pole MCCB footprint — it occupies four 25 mm (1-inch) module spaces on a DIN rail or bolts directly to a mounting plate. The 70 mm depth means it clears most 200 mm deep enclosures with room for rear busbars. Front IP40 protection handles typical panel environments; no special gasketing needed for dry indoor installs.
Key electrical ratings at a glance
Rated insulation voltage (Ui) is 690 VAC, and maximum DC operational voltage is 500 VDC — so it works in both AC distribution and DC battery-bank or UPS circuits up to that limit. The TM220 release has an adjustable li max of 400 A for the short-circuit pickup, giving flexibility to coordinate with downstream breakers. Power loss maxes at 11 W, which is modest for a 40 A frame — helps keep the enclosure thermal rise under control.
What's not on this breaker
No communication function, no ground-fault monitoring, no motor drive, and no N-conductor protection built in. If you need remote trip signaling or GFCI, you're looking at a different 3VM variant or an add-on accessory. The neutral conductor is not upgradeable or retrofittable on this frame — if your design requires a switched neutral, spec the N-pole version from the start.