當市(shi)電(dian)(dian)供電(dian)(dian)中斷或(huo)市(shi)電(dian)(dian)電(dian)(dian)壓(ya)超限 (±15%或(huo)±20%額(e)定輸(shu)入電(dian)(dian)壓(ya))時,互投裝(zhuang)置將立即投切(qie)至(zhi)逆(ni)變器供電(dian)(dian),在(zai)電(dian)(dian)池組所提供的(de)(de)直流能源的(de)(de)支持下(xia),此時,用(yong)戶負(fu)載所使用(yong)的(de)(de)電(dian)(dian)源是(shi)通(tong)過EPS的(de)(de)逆(ni)變器轉換的(de)(de)交流電(dian)(dian)源,而不是(shi)來自市(shi)電(dian)(dian)