Silig dahaaran oo saddex jibbaaran ama silig dahaaran oo la xoojiyay oo ka kooban saddex lakab, ayaa gebi ahaanba ka goynaya heerka koowaad ee beddelka.Dahaarka la xoojiyay wuxuu bixiyaa heerar kala duwan oo badbaado ah oo baabi'iya caqabadaha, cajaladaha lakabyada dhexdooda ah iyo tuubooyinka dahaadhka ah ee ku jira beddelka.
Faa'iidada ugu badan ee siligga saddex-laaban ee dahaaran ma aha oo kaliya koronta burburka sare ee ilaa 17KV, laakiin marka lagu daro dhimista cabbirka iyo dhaqaalaha kharashyada agabka wax-soo-saarka transformer-ka.