The three poles mean it switches all three phases in a three-phase circuit — standard for motor branch circuits, lighting panels, and feeder taps up to its rated current.
What the 3-pole rating means for fit
A 3-pole configuration on a molded case switch means the part breaks all three phases simultaneously on a trip or manual open command. That matters for any three-phase load — motor starters, HVAC units, pumps, compressors — where single-phasing downstream would damage the equipment. If your BOM specifies a 3-pole disconnect, this unit matches that requirement directly.