ZDDQ low voltage metal enclosed automatic multi-step capacitor banks improves power factor in systems with variable energy demand and non-linear loads, therefore, with variable reactive load needs. Metal enclosed automatic multi-step capacitor banks ,equipped with a power factor controller to regulate their automated operation and monitoring features, ZDDQ automatic capacitor banks remove power factor charges of the electricity bill and reduce the losses of electrical equipment and wiring by power factor improvement and harmonics fitering.