ABSTRACT To calculate the complete fusion cross section over all partial waves, as a function of the excitation energy, the maximum values of angular momentum 1max represents the upper limit of that summation . An effective definition for that limit has been checked . Also a comparison with the fusion and critical limits ,1fus and 1cr respectively, has been displayed . The effect of the nuclear part of the barrier height and the approximation technique have been checked to approach the best fit of the measured fusion excitation functions .