Siemens SENTRON 3VA1163-3EF32-0BH0 — 63 A MCCB with Undervoltage Release
The Siemens SENTRON 3VA1163-3EF32-0BH0 is a 3-pole molded case circuit breaker (MCCB) rated for line protection, carrying a continuous current of 63 A at 40 °C and derating to 58 A at 70 °C. Its interrupting capacity reaches 75.6 kA at 240 V, 52.5 kA at 415 V, and 11.9 kA at 690 V — figures that govern fault-clearing coordination downstream. The breaker ships with an integrated undervoltage release (UVR) and a complement of 2 auxiliary switches plus 1 trip alarm switch (HQ), so it arrives ready for remote status indication and undervoltage tripping without a separate add-on module.
What the Ratings Mean for Panel Fit
The 63 A rating at 40 °C is the thermal benchmark for continuous load — the breaker holds that current indefinitely without tripping in a 40 °C ambient. Above that, the thermal-magnetic trip unit derates: 62 A at 55 °C, 60 A at 65 °C, 58 A at 70 °C. If your panel ambient runs hotter, size the feeder for the derated value, not the 63 A nameplate. The 75.6 kA breaking capacity at 240 V tells you this MCCB can safely interrupt a fault current up to that level without welding contacts or rupturing the case — critical for high-fault installations like transformer secondaries or large motor control centers. The 800 V rated insulation voltage confirms it is suitable for 690 V line-to-line systems with margin.
Built-in Auxiliary Switches and Undervoltage Release
This variant includes an undervoltage release (UVR) as the auxiliary release type — when control voltage drops below the dropout threshold, the UVR trips the breaker, providing machine-safe power removal on loss of control power. The auxiliary switch complement (2 form-C contacts + 1 trip alarm switch) fits standard 3VA accessory slots; no extra wiring space needed beyond the breaker's own terminal layout. The trip indicator (mechanical flag) gives a local visual confirmation of trip cause without opening the panel door.