The dynamical reconfiguration of the photovoltaic array is a feasible method for maximizing the electrical power it produces in presence of partial shading. Although in literature some algorithms aimed at determining the best configuration to be settled for a given shadowing pattern have been presented, no indications about the electrical conditions that can trigger the reconfiguration procedure have been discussed. In this paper some criteria for understanding if the photovoltaic array working conditions have changed, so that a new electrical connection among the modules can increase the produced power, are discussed. Moreover, some conditions revealing that the reconfiguration process can be delayed are analyzed as well. Simulation results are used for achieving the results shown in the paper and give some indications for improving the criteria formulated herein.