Umba wamandla (PF) ngumlinganiselo wamandla okusebenza, alinganiswa ngeekilowathi (kW), ukuya kumandla abonakalayo, alinganiswa ngekhilovolti amperes (kVA). Amandla abonakalayo, ekwabizwa ngokuba yimfuno, ngumlinganiselo wobungakanani bamandla asetyenziselwa ukuqhuba oomatshini kunye nezixhobo ngexesha elithile. Ifunyanwa ngokuphindaphinda (kVA = V x A)