Inkqubo enxuseneyo kukusombulula ingxaki yokutshaja kwebhetri enevoltheji ephezulu kwipakethi yebhetri yombane ophantsi ngenxa yomohluko wombane phakathi kweepakethi zebhetri.
Ngenxa yokuba ukuchasana kwangaphakathi kweseli yebhetri kuphantsi kakhulu, ngoko ke umbane wokutshaja uphezulu kakhulu, ojongene nobungozi.Sithi 1A, 5A, 15A ibhekisela kumda olinganiselweyo wokuhlawula ibhetri.