當市電(dian)(dian)供電(dian)(dian)中斷或(huo)(huo)市電(dian)(dian)電(dian)(dian)壓超限 (±15%或(huo)(huo)±20%額定輸入電(dian)(dian)壓)時(shi),互投裝(zhuang)置將立即投切至(zhi)逆變器供電(dian)(dian),在電(dian)(dian)池組所提供的(de)(de)(de)直(zhi)流能源的(de)(de)(de)支持(chi)下,此時(shi),用(yong)戶負(fu)載所使用(yong)的(de)(de)(de)電(dian)(dian)源是通(tong)過EPS的(de)(de)(de)逆變器轉換的(de)(de)(de)交流電(dian)(dian)源,而不是來自市電(dian)(dian)