What this MCCB is and what it protects
The Siemens SENTRON 3VA2140-8HL46-0AA0 is a 4-pole molded case circuit breaker (MCCB) rated for 40 A continuous current, designed for line protection in distribution panels. It carries an ETU320 electronic overcurrent release, which gives you adjustable thermal-magnetic or electronic trip curves depending on the release variant — here it's the electronic trip unit with LSI protection (long-time, short-time, instantaneous). The 800 V rated insulation voltage means it's comfortable on 400/480 VAC systems with headroom for voltage sags.
Breaking capacity — what the ratings mean for your fault duty
Breaking capacity is the maximum fault current this breaker can safely interrupt without welding contacts or venting plasma. At 240 V it's rated 440 kA — that's a very high interrupting rating, typical for a current-limiting MCCB used close to the transformer secondary. At 415/440 V it's 330 kA, at 500 V it's 220 kA, and at 690 V it's 52.5 kA. These numbers tell you the breaker can handle high available fault currents on low-voltage systems, but you still need to verify the SCCR at your specific system voltage and the upstream protective device coordination.
Physical fit — panel space and mounting
The breaker measures 140 mm wide, 181 mm high, and 86 mm deep. That 140 mm width is a standard 4-pole MCCB footprint — it occupies roughly 5.5 inches of DIN-rail or panel-mount space. The depth of 86 mm (3.39 in) matters when you're laying out the gland plate or enclosure depth; it's a relatively shallow breaker, so it clears most 200 mm deep enclosures without crowding the door or busbars. IP40 on the front means it's protected against tools and wires >1 mm, but it's not sealed against dust ingress — keep it in a clean, indoor panel.
What the ETU320 release gives you
The ETU320 is an electronic trip unit with LSI protection — long-time delay (L), short-time delay (S), and instantaneous (I). It's adjustable, so you can set the pickup and delay to coordinate with downstream breakers and avoid nuisance trips on motor inrush or transformer energization. The 40 A continuous rating is the frame's maximum; you can set the long-time pickup lower if the load draws less. The electronic trip also gives you better accuracy and temperature stability than a thermal-magnetic release, which matters if the panel ambient runs warm — note the breaker is rated full 40 A all the way up to 70 °C ambient, so no derating needed in a hot enclosure.
Temperature performance — no derating up to 70 °C
The breaker carries its full 40 A rating across the entire operating temperature range from -25 °C to 70 °C. That's unusual — most MCCBs start derating above 40 °C. Here, the continuous current stays at 40 A at every 5 °C step from 40 °C through 70 °C. If your panel is in a hot factory, boiler room, or outdoor cabinet in direct sun, this breaker won't force you to oversize the frame just to handle the ambient heat. Storage range is -40 °C to 80 °C, which is typical for shipping and warehousing.
Power loss and auxiliary functions
Maximum power loss is 1.2 W — negligible for thermal budgeting in a panel. The breaker has no undervoltage release, no voltage trigger, no trip indicator, and no communication function. It's a straight line-protection device: no bells, no remote monitoring. If you need shunt trip, UVR, or auxiliary contacts, those are add-on accessories that mount to the breaker's accessory slots, but they're not included on this order code. Ground-fault monitoring is also not built in.