What this MCCB carries on the BOM
The Siemens 3VA1112-5MH32-0CH0 is a 3-pole IEC frame 160 molded case circuit breaker with a 125 A thermal-magnetic release (TM120M, AM characteristic) and a breaking capacity class M rated at Icu=55 kA at 415 V AC. It ships without overload protection — the TM120M provides short-circuit protection only, with adjustable instantaneous pickup Ii=5…15 × In. The order code includes an undervoltage release (UVR) for 120-127 V AC 50/60 Hz, two HQ auxiliary switches, one HQ trip alarm switch, and a nut keeper kit for the mounting hardware.
What the ratings mean for fit
The 55 kA Icu at 415 V AC places this breaker in the M (medium) breaking capacity class per IEC 60947-2 — sufficient for most industrial distribution panels where the prospective short-circuit current at the main bus does not exceed that level. The TM120M magnetic-only release (no thermal overload element) means this breaker is intended for motor starter protection where overload protection is handled by a separate overload relay; the adjustable instantaneous trip (5–15 × In) lets you coordinate with the motor inrush without nuisance tripping. The UVR coil drops the breaker on loss of control voltage, a common requirement for emergency-stop circuits or undervoltage protection schemes.