What is the unit of measure for capacitor power noted on nameplates?

The unit of measure for capacitor power noted on nameplates is typically expressed in kVAR, which stands for kilovolt-amperes reactive. Capacitors are used in electrical systems primarily to improve power factor, thus they do not directly provide real power (measured in kW), but rather reactive power, which influences the voltage levels in the system and helps manage the reactive load.

Reactive power is associated with the energy storage capability in the electric field of the capacitor. Unlike kW, which indicates the real, usable power in a circuit, kVAR describes the power that does not perform any useful work but is essential for maintaining the voltage levels required for system stability.

Nameplates of capacitors reflect kVAR to inform users about the amount of reactive power the capacitor can provide or absorb, thus playing a crucial role in power factor correction and enhancing the efficiency of electrical systems. Other units like kJ, which represents energy, and kVA, which denotes apparent power, do not serve the same purpose in the context of capacitor rating.