Kumjikelezo we-AC, kukhona imiqondo emithathu yamandla kagesi: amandla asebenzayo, amandla asebenzayo namandla abonakalayo. I-KVA imele amandla abonakalayo, afaka amandla asebenzayo namandla asebenzayo. I-KW imele amandla asebenzayo, futhi i-kVar imele amandla asebenzayo. Ubudlelwano phakathi kwe-kW ne-kVar kanye nokuguqulwa kunomqondo - isici samandla esithi cos ф, amandla asebenzayo kW=UIcos ф, amandla asebenzayo kVar=UIsin ф, namandla abonakalayo kVA=UI(U ingu-voltage, mina ingamanje).