The act of balancing the incoming power across all 3 phases. All incoming power on a 3 phase supply must be actively power balanced to avoid breakers tripping out. This applies to all UPS’s and Generators. No make is immune. Every UPS from Riello UPS Power Supplies, Eaton UPS Power Supplies, AEC UPS power supplies and Emerson Leibert, must have its load carefully checked and balanced across they three phases.