The Siemens 3VM1125-5EE36-0AA2 is a 3-pole IEC molded-case circuit breaker from the 3VM1 series, frame size 160. It carries a 55 kA breaking capacity at 415 V (class M), with a rated current In of 25 A and an adjustable thermal-magnetic trip unit (TM220, ATFM). Overload protection Ir is settable from 18 A to 25 A; short-circuit protection Ii is fixed at 12.8 × In.
Breaking capacity and protection settings
The 55 kA Icu at 415 V means this breaker safely interrupts fault currents up to that level without welding or rupturing — essential for high-fault-capacity industrial panels where upstream transformers or large motors can feed substantial short-circuit energy. The 25 A frame with adjustable Ir (18–25 A) lets you fine-tune the overload pickup to match the protected conductor or load, avoiding nuisance tripping on inrush while still clearing sustained overloads. The fixed magnetic trip at 12.8 × In (320 A) is set for motor-start or high-inrush applications; it clears hard shorts fast without needing a separate instantaneous adjustment.