當市電(dian)(dian)(dian)供電(dian)(dian)(dian)中斷或市電(dian)(dian)(dian)電(dian)(dian)(dian)壓超限 (±15%或±20%額定(ding)輸入電(dian)(dian)(dian)壓)時,互投(tou)裝置(zhi)將立即(ji)投(tou)切至(zhi)逆變器(qi)供電(dian)(dian)(dian),在(zai)電(dian)(dian)(dian)池組所提(ti)供的直(zhi)流能源(yuan)(yuan)的支持下(xia),此時,用(yong)戶負載所使用(yong)的電(dian)(dian)(dian)源(yuan)(yuan)是(shi)通過EPS的逆變器(qi)轉換(huan)的交流電(dian)(dian)(dian)源(yuan)(yuan),而不是(shi)來自(zi)市電(dian)(dian)(dian)