What this breaker carries
The Siemens 3VA1125-4EE32-0KH0 is a 3-pole IEC frame 160 circuit breaker in breaking capacity class S, rated Icu=36kA at 415 V. That interrupting rating means it clears a fault up to 36 kA without welding or rupturing — enough for most industrial distribution panels downstream of a transformer. The TM220 thermal-magnetic trip unit gives fixed thermal (Ir=18…25 A) and fixed magnetic (Ii=12.8 x In) protection, so the breaker coordinates with typical motor-start and feeder loads without needing a separate adjustment module. This variant ships with a shunt trip (STL) rated 220-250 V DC / 208-277 V AC, plus two auxiliary switches HQ and one trip alarm switch HQ. The shunt trip allows remote tripping from an E-stop or PLC output; the aux switches give status feedback to a DCS or panel lamp. The nut keeper kit is included — a small but time-saving detail when mounting in a high-vibration panel.
Panel integration notes
The 3VA1 frame mounts on a DIN rail or can be screw-fixed to a backplate. At 25 A and 36 kA SCCR, it fits in a standard 3-pole MCCB footprint — watch the space for the shunt trip and auxiliary switch stack, which adds depth behind the cover. The nut keeper kit prevents loose hardware during transport, a common failure point on field-installed breakers.