An Automatic Power Factor Control (APFC) panel is an electrical device that improves power factor by automatically switching capacitor banks on and off. Power factor is the ratio of active power to apparent power, and it's a key factor in measuring electrical consumption. Most electrical loads are reactive, which can result in poor power factor. APFC panels can help improve power factor by delivering reactive power to inductive loads as needed. This can also boost voltage and improve the lifespan of electrical equipment. 

APFC panels can be used in electrical systems with stable load profiles and constant reactive power demand. They can be modular, wall mounted, or foot mounted, and come in different stages, ratings, and with different features. For example, some APFC panels may include incomer MCCBs and capacitor duty contactors.