Kwisekethe ye-AC, kukho iikhonsepthi ezintathu zamandla ombane: amandla asebenzayo, amandla asebenzayo kunye namandla abonakalayo. I-KVA imele amandla abonakalayo, aquka amandla asebenzayo kunye namandla asebenzayo. I-KW imele amandla asebenzayo, kwaye i-kVar imele amandla asebenzayo. Unxulumano phakathi kwe-kW kunye ne-kVar kunye noguqulo kukho uluvo - umba wamandla cos ф, amandla asebenzayo kW=UIcos ф, amandla asebenzayo kVar=UIsin ф, kunye namandla abonakalayo kVA=UI(U yivoltage, mna ngokwangoku).