以單相110V耗電流10A舉例
功率 P = V * A , P = 110V * 10 A = 1100 VA
功因 PF = 0.7~1(依實際Power算)
實功率 W = V * A * PF = 1100VA * 0.7 = 770 W
虛功率 Q = V * A * (1-PF) = 1100VA * 0.3 = 330 Var
度 = KW * Hour = 770W * 1 Hour = 0.77度