Capacitors have been used to provide reactive power compensation in distribution systems. They are provided to minimize power losses and to maintain voltage profile within in the acceptable limits. The capacitor placement problem is a well researched topic and has been addressed by many researchers. Most of the approaches have the common defect of being caught to a local solution whereas Particle Swarm Optimization (PSO) searches for a global solution using multiple paths. A new approach for finding the optimal size and location of capacitors using PSO is reported in this work. The problem is how to optimally determine the location to install capacitors, the types and sizes of capacitors to be installed and during each load level, the control schemes for each capacitor in the nodes of a general 3-phase radial distribution networks such that a desired objective function is minimized, while the load constraints, network constraints and operational constraints at different load levels are satisfied.