The ABB A2N175TW is a 3-pole molded case circuit breaker from the A2N 250 frame, fitted with a TMF 175-1750 thermal-magnetic fixed trip unit. The TMF designation means the thermal (overload) element is fixed at 175 A and the magnetic (short-circuit) element is fixed at 1750 A — no field-adjustable dials, so the trip curve is locked to those values. This is a panel-mount device intended for distribution and motor branch-circuit protection in switchboards and industrial enclosures.
The 1750 A fixed magnetic pickup means the instantaneous trip fires at 10× the thermal rating, which is typical for a thermal-magnetic MCCB protecting a motor branch or a feeder with moderate inrush. Because the trip unit is non-interchangeable, the breaker is dedicated to that one amp setting; if the load changes, the whole breaker must be swapped. Mounts in a standard ABB A2N 250 frame cutout, with line and load lugs sized for the 175 A continuous rating.