Idan aka kwatanta da ƙanana da matsakaita masu girma dabam, manyan motocin lantarki suna da tsada, kuma yanayin aikace-aikacen su yana da mahimmanci kuma na musamman. Ko zubar da jikin motar ne bayan kuskure ko wasu matsalolin da aka samo daga laifin, yana iya zama mafi tsanani fiye da yadda za mu iya tsammani. Don haka, ana amfani da na'urorin kariya daban-daban don injunan lantarki masu ƙarfi da ake amfani da su a wasu lokuta na musamman, waɗanda manufarsu ita ce gano matsaloli cikin lokaci da inganci da kuma hana ci gaba da tabarbarewar matsalolin.
Kariya daban-daban shine ma'aunin kariya mai tasiri sosai don amintaccen aiki na kayan lantarki. Yana amfani da halaye na haifar da ayyukan kariya ta hanyar bambance-bambancen vector tsakanin shigar da halin yanzu da fitarwa na kayan lantarki, yin duk wata hanyar sadarwa ta lantarki mai tashar jiragen ruwa biyu, janareta, injin, taswira da sauran kayan lantarki suna da aikace-aikace na yau da kullun. Kariyar bambance-bambance yana da ɗanɗano ana amfani da shi sosai akan manyan injina masu ƙarfin lantarki. Misali, manyan injinan wutan lantarki da ake amfani da su a cikin babban wutar lantarki na ma'adanan da manyan kayan aikin iska dole ne a sanye su da na'urorin kariya daban-daban don tabbatar da aminci da amincin aiki na tsarin da kuma guje wa manyan asarar tattalin arziki da haɗarin aminci da ke haifar da rufewar ba zata. The stator windings na manyan high-voltage Motors yawanci daukan tauraro dangane, tare da fitarwa tashoshi uku ta tsohuwa. Lokacin da aka gabatar da kariyar bambance-bambance, motar dole ne ta sami tashoshi 6 na fitarwa. Na'urar kariya ta bambance-bambancen da aka yi amfani da ita a kan motar tana aiki kamar haka: gano madaidaicin farawa da ƙarewar motsin motar, kuma kwatanta lokaci da girman bambancin tsakanin igiyoyin farawa da ƙarewa. A karkashin yanayi na al'ada, bambanci a cikin amplitude da lokaci tsakanin maɗaukakiyar farawa da ƙarewa ba kome ba ne, wato, halin da ke gudana a cikin motar yana daidai da halin yanzu da ke gudana daga cikin motar; lokacin da ɗan gajeren kuskure kamar lokaci-zuwa-lokaci, juyawa-zuwa-juya ko zuwa ƙasa ya faru a cikin motar, ana haifar da bambanci tsakanin su biyun kuma ya kai wani ƙima, aikin kariya yana kunna.