The ABB A40-30-10-84RT is a 3-pole contactor rated for 40 A in AC-3 duty, meaning it handles motor switching up to that current — typical for controlling pumps, conveyors, and compressors in industrial control panels. It carries one normally open auxiliary contact for status feedback or interlocking.
What the key rating means for fit
The 40 A AC-3 rating is the motor-switching current. AC-3 covers starting and plugging — the contactor must handle inrush. The single NO auxiliary is enough for a run-status signal but not for a full interlock chain; if your circuit needs NC feedback or multiple auxiliaries, you'll need a different variant.