(1) Cov khoom siv faib khoom tseem ceeb, suav nrog hu ua lub chaw faib hluav taws xob. Cov no yog nruab nrab nruab nrab hauv lub chaw lag luam substation, faib hluav taws xob hluav taws xob kom qis dua - cov khoom siv faib khoom hauv ntau qhov chaw. Cov khoom siv qib no nyob ze rau cov kauj ruam -down transformer, yog li yuav tsum tau muaj hluav taws xob ntau dua thiab muaj peev xwm ua tau ntau dua.
(2) Cov khoom siv faib khoom thib ob, cov lus sib sau ua ke rau cov khoom siv hluav taws xob faib hluav taws xob thiab cov chaw tswj lub cev muaj zog. Cov khoom siv hluav taws xob faib hluav taws xob yog siv nyob rau hauv cov xwm txheej uas cov khoom thauj tau sib cais thiab muaj tsawg dua circuits; cov chaw tswj lub cev muaj zog yog siv nyob rau hauv cov xwm txheej uas cov load yog concentrated thiab muaj ntau circuits. Lawv faib cov hluav taws xob hluav taws xob los ntawm lub voj voog ntawm yav dhau los - cov khoom siv faib khoom mus rau qhov ze tshaj plaws. Cov cuab yeej siv qib no yuav tsum muaj kev tiv thaiv, kev saib xyuas, thiab kev tswj xyuas kev thauj khoom.
(3) Thaum kawg - cov khoom siv faib tawm theem, sib sau ua ke hu ua lub teeb hluav taws xob faib lub thawv. Cov no nyob deb ntawm qhov chaw muab hluav taws xob thiab muab faib, me me - cov khoom siv muaj peev xwm.
