What the 250V 3-pole rating means for fit
The XT4V250-100A: The 250V 3-pole rating tells you this breaker is sized for a 3-phase system with a line-to-line voltage up to 250 VAC — typically a 240V delta or 208Y/120V wye service. Each pole switches one phase, so the three poles together interrupt all three lines. The molded case construction gives it a higher interrupting capacity than a miniature breaker of similar current, making it suitable for main or feeder duty in a panel where fault current may be substantial. If your BOM calls for a 250V 3-pole MCCB, this order code is the direct fit.