Circuit Court breakers ua tiav ob lub luag haujlwm hauv lub tshuab hluav taws xob: ua ntej, kev tswj hwm kev ua haujlwm -tshwj xeeb, nqa cov khoom siv hluav taws xob tshwj xeeb lossis cov kab xa mus rau hauv lossis tawm ntawm kev pabcuam raws li kev ua haujlwm ntawm lub zog hluav taws xob; thiab thib ob, kev tiv thaiv kev ua haujlwm-xws li, yog tias muaj teeb meem hauv cov khoom siv hluav taws xob lossis cov kab, ua los ntawm cov khoom siv tiv thaiv relay kom cais cov ntu tsis raug ntawm lub zog hluav taws xob sai, yog li ua kom muaj kev ua haujlwm ntawm qhov tsis raug- seem dawb.
Txawm hais tias muaj ntau hom kev siab -voltage circuit breakers, hais lus, lawv txhua tus muaj tsib yam tseem ceeb: cov khoom cuam tshuam, txhawb cov insulators, cov khoom sib kis, lub hauv paus, thiab cov txheej txheem kev ua haujlwm. Lub ntsiab lus cuam tshuam ua haujlwm yog lub hauv paus tseem ceeb ntawm lub Circuit Court breaker, lub luag haujlwm rau kev ua tiav txhua yam haujlwm ntsig txog kev tswj hwm, kev tiv thaiv, thiab kev ua haujlwm zoo sib xws. Cov khoom seem yog tsim los ua haujlwm ua ke nrog cov khoom cuam tshuam los pab txhawb kev ua tiav ntawm cov haujlwm uas tau hais los saum no.