Siemens SENTRON 3VA1120-3EF36-0CC0 — 20 A MCCB with Undervoltage Release
The Siemens SENTRON 3VA1120-3EF36-0CC0 is a 3-pole molded case circuit breaker (MCCB) rated 20 A at 40 °C, designed for line protection in distribution panels. Its 75.6 kA breaking capacity at 240 V gives selectivity headroom downstream of a larger feeder — the SCCR at 415 V is 52.5 kA, at 440 V it holds 32 kA, and at 690 V it still interrupts 11.9 kA, so this breaker coordinates cleanly with switchgear on either side of the voltage step. Rated insulation voltage is 800 V, and the unit carries an undervoltage release (UVR) plus two factory-fitted auxiliary switches HQ — a configuration that saves panel space versus adding a separate shunt-trip module and aux contact block later. Maximum power loss is 14.5 W, which matters when calculating thermal rise in a sealed enclosure.
Panel Fit — Dimensions and DIN-Rail Mounting
Width of 76.2 mm (3 in) is the standard 3-pole MCCB footprint for this SENTRON frame size — it occupies three 25.4 mm module positions on a DIN rail. Depth of 70 mm (2.76 in) and height of 130 mm (5.12 in) leave clearance for the UVR coil and auxiliary switch wiring; verify the enclosure depth against the 70 mm plus wiring bend radius.