What It Is and What It Does
The Siemens SENTRON 3VA1120-5EF32-0JH0 is a 3-pole molded case circuit breaker (MCCB) rated for line protection in distribution panels. It carries a continuous current of 20 A at 40 °C ambient — the same rating holds through 55 °C, then derates to 19 A at 60–70 °C, so it holds the thermal profile across a typical enclosure temperature range without nuisance tripping. Breaking capacity is the headline: 187 kA at 240 V AC, 121 kA at 415 V, 75.6 kA at 440 V, and 17 kA at 500/690 V. That SCCR headroom covers high-fault industrial feeds — the 187 kA figure at 240 V means it safely interrupts faults up to that level without cascading upstream, critical for a main or feeder breaker in a high-capacity panel. The breaker includes a shunt trip release (STL) for remote opening and comes fitted with 2 auxiliary switches plus 1 trip alarm switch (HQ configuration). Power loss at full load is 12 W maximum. Insulation voltage rated 800 V, operating range -25 °C to 70 °C, storage from -40 °C to 80 °C.
Panel Integration and Fit
Dimensions: 130 mm height, 76.2 mm width, 70 mm depth. The 3-pole frame mounts into standard SENTRON panel-mounting cutouts and bus-bar systems — no special adapter plate needed for a 3VA-series retrofit. The auxiliary and alarm switch wiring lands on the integrated terminal block; the shunt trip coil is wired separately.