當市(shi)電(dian)(dian)(dian)供(gong)電(dian)(dian)(dian)中斷或(huo)市(shi)電(dian)(dian)(dian)電(dian)(dian)(dian)壓超限 (±15%或(huo)±20%額(e)定輸入電(dian)(dian)(dian)壓)時,互投(tou)裝置將立即投(tou)切(qie)至逆(ni)(ni)變器供(gong)電(dian)(dian)(dian),在(zai)電(dian)(dian)(dian)池組所提(ti)供(gong)的(de)直流能(neng)源的(de)支(zhi)持(chi)下,此時,用(yong)戶(hu)負(fu)載所使(shi)用(yong)的(de)電(dian)(dian)(dian)源是通過EPS的(de)逆(ni)(ni)變器轉換的(de)交流電(dian)(dian)(dian)源,而不是來自市(shi)電(dian)(dian)(dian)