用來保(bao)護線路和風機的過載及(ji)短(duan)路。
本電(dian)(dian)控箱(xiang)電(dian)(dian)源(yuan)為(wei)三相(xiang)五(wu)線制供電(dian)(dian),三相(xiang)電(dian)(dian)源(yuan)可上進,也可下進。接至電(dian)(dian)控箱(xiang)底部的端子排中,裝設的自動(dong)空氣(qi)開關QF作(zuo)雙速風機(ji)短路保護(hu),熱(re)繼電(dian)(dian)器FR用作(zuo)低(di)速過載保護(hu)。
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