Izimbangela zeInjini ye-AC enezigaba ezintathuukutubeka kungahlukaniswa kube umthwalo, ukunikezwa kwamandla, ukufakwa kwezimoto, nokulahlekelwa kwesigaba.
Ukutubeka kwesigaba sesithathu se-AC motor (ukulayishwa ngokweqile): Ngaphansi kokusebenza okugcwele kakhulu, injini iyashisa. Noma injini iqala njalo futhi injini ishisa ngokweqile. Lapho zombili iziphetho ze-stator zishiswa ngaphakathi kwemoto futhi izingxenye ezishile ziba umfaniswano (ngokuvamile, injini inamandla okusebenza angashintshi, abizwa ngokuthi amandla alinganiselwe, ngama-watts (w), futhi kwezinye izimo amandla angempela asetshenziswa injini edlula amandla alinganisiwe emoto, lesi simo sibizwa ngokuthi i-motor overload. Izimbangela zesigaba sesithathu se-AC motor power iyancipha, i-voltage iba mkhulu kakhulu ishisa kakhulu. I-voltage yokuhlinzeka ngogesi iphezulu kakhulu, futhi umshini wokosa inyama uyavutha.
Izimbangela zesigaba sesithathu se-AC motor insulation: I-insulation yangaphakathi ye-motor ayihlangabezani nendinganiso, futhi kukhona ukujikeleza okufushane kwesigaba kuya kwesigaba phakathi kokujika. Noma izintambo zangaphakathi azilungile. Lo mshini wokosa inyama ngezinye izikhathi udidaniswa kalula nomshini wokosa inyama ogcwele ngokweqile, futhi i-stator nayo izosha, kodwa kukhona izimpawu zokusha ezisobala engxenyeni ye-short-circuit, njengensimbi encibilikisiwe yethusi ngezinye izikhathi. Ingxenye ejikajikayo ishiswe kabi. Izizathu zokushiswa kwenjini ye-AC enezigaba ezintathu yilezi: 1. Imotor kagesiyamukela iuxhumano lwe-delta (isigaba esi-3)indlela, futhi isigaba esisodwa kuphela sokusonga singashiswa. Sebenzisa i-megohmmeter ukuze ulinganise umonakalo wokufakelwa kwesigaba esisodwa sokusonteka phansi. 2. I-motor ithatha indlela yokuxhumana yenkanyezi (y), futhi izigaba ezimbili zokusonta ziyashiswa. Ungasebenzisa i-megohmmeter (iwashi) ukukala umonakalo wokufakwa kwezigaba ezimbili zokusonteka phansi.