The Siemens 3VA1463-5EF32-0CB0 is a 3-pole IEC frame 630 molded case circuit breaker with a 55 kA interrupting capacity at 415 V AC (breaking capacity class M). It's built for line protection on high-current feeders or large motor branch circuits where you need selective coordination downstream. The TM240 thermal-magnetic trip unit gives you an adjustable overload protection range (Ir) from 440 A to 630 A, and a short-circuit pickup (Ii) adjustable from 4 to 8 times the rated current In of 630 A. That range covers most 400–600 A feeder applications without needing a separate relay. This variant ships with an integrated undervoltage release rated 120–127 V AC 50/60 Hz and two auxiliary switches (changeover contacts). The UVR trips the breaker on loss of control voltage — standard for safety circuits where a downstream contactor or safety relay must drop power on undervoltage.
What the Ratings Mean for Fit
The 55 kA Icu at 415 V defines the maximum fault current the breaker can safely interrupt without welding contacts or rupturing the arc chamber. In a panel with a transformer rating above 1.5 MVA or a utility service of 50+ kA available fault current, this breaker gives you the headroom to stay coordinated with downstream 25 kA or 36 kA devices. The adjustable Ir (440–630 A) and Ii (4–8× In) mean you can dial the overload pickup to match the actual continuous load and the magnetic pickup to ride through motor inrush without nuisance tripping. For a 500 A feeder feeding a group of motors, set Ir at 500 A and Ii at 6× In (3780 A) — that clears a bolted fault fast but lets a 6× starting current pass for 100 ms. The integrated undervoltage release (120–127 V AC) and two auxiliary switches eliminate the need for separate accessory modules on the breaker side. The UVR coil draws a low holding current — verify the control transformer sizing if you're daisy-chaining multiple UVRs on the same 120 V control circuit.