Siemens SENTRON 3VA2140-6HK36-0AA0 — 40 A MCCB with ETU340 Trip
The Siemens SENTRON 3VA2140-6HK36-0AA0 is a 3-pole molded case circuit breaker (MCCB) rated for line protection at 40 A continuous current, carrying an ETU340 electronic trip unit. This is the go-to breaker for a 40 A feeder or downstream sub-distribution in a commercial or industrial panel — the ETU340 gives you adjustable long-time, short-time, and instantaneous pickup, plus ground-fault alarm or trip if you wire the optional module. The 40 A rating holds flat from 40 °C up to 70 °C, so no derating headache in a warm enclosure. Breaking capacity runs 242 kA at 240 V and 187 kA at 415 V, which covers most utility transformer fault levels in North America and Europe. At 690 V it drops to 3.7 kA — still fine for a 690 V motor branch where the source transformer is small or impedance-limited.
Breaking Capacity and Trip Curve — What the Ratings Mean for Your Panel
The 242 kA at 240 V is the ultimate short-circuit current the breaker can interrupt without welding or rupturing — that's the SCCR for a 240 V delta or 277/480 V wye service entrance. At 415/440 V it still holds 187 kA, which covers the high-fault end of a 400 V industrial distribution. The ETU340 is an electronic trip with an LSI curve: long-time pickup adjustable from 0.4x to 1.0x In (16 A to 40 A), short-time pickup and delay for selective coordination downstream, and instantaneous fixed at 10x In (400 A). That means you can set it to ride through motor inrush and still clear a bolted fault in under 100 ms. The breaker is IP40 on the front — protected against tools and wires >1 mm, but not sealed against water, so it belongs in a dry indoor panel.
Physical Fit — DIN Rail or Direct Mount
The 3VA2140-6HK36-0AA0 measures 105 mm wide, 181 mm high, and 86 mm deep. That width is the standard 3-pole MCCB footprint for the SENTRON 3VA platform — it fits the same mounting base and busbar system as other 3VA breakers. Mounting is via four M6 screws on a backplate or onto a DIN rail adapter (sold separately). The 86 mm depth leaves clearance for rear-connected busbars or a cable-entry gland plate. Panel builders: plan for 105 mm per pole width plus 5 mm side gap for heat dissipation.