In an AC circuit, power and VA mean the same thing only when there is no reactance .
Reactance is introduced when a circuit contains an inductor or capacitor .
Because most AC circuits contain reactance, the VA figure is greater than the actual dissipated or delivered power in watts. This can cause confusion in specifications for power supplies. This does not mean it can deliver 600 watts, unless the equipment is reactance-free. Also see current , voltage , power , reactance , and watt . Bringing you the best technology specific search engines.