Ulalo wopindika wa unyolo umagwiritsidwa ntchito kulumikiza zingwe ku insulator, kapena kulumikiza zotchingira ndi zingwe za waya pansi ku zida za nsanja kapena zida zogonjetsera. Zopangira maulalo zimakhala ndi mtundu wapadera komanso mtundu wamba malinga ndi momwe amakwezera. Mtundu wapadera umaphatikizapo mpira-diso ndi socket-diso kulumikiza ndi insulators. Mtundu wamba nthawi zambiri umakhala mtundu wolumikizidwa ndi pini. Amakhala ndi magiredi osiyanasiyana malinga ndi katundu ndipo amatha kusinthana ndi giredi yomweyo.