An extension of the standard model to the local gauge group ${\mathrm{SU}(3)}_{c}\ensuremath{\bigotimes}{\mathrm{SU}(3)}_{L}\ensuremath{\bigotimes}{U(1)}_{X}$ as a family independent model is presented. The mass scales, the gauge boson masses, and the masses for the spin 1/2 particles in the model are studied. The mass differences between the up and down quark sectors, between the quarks and leptons, and between the charged and neutral leptons in one family are analyzed. The existence of two Dirac neutrinos for each family, one light and one very heavy, is predicted. By using experimental results from CERN LEP, SLC and atomic parity violation we constrain the mixing angle between the two neutral currents and the mass of the additional neutral gauge boson to be $\ensuremath{-}0.00015<~\mathrm{sin}\ensuremath{\theta}<~0$ and $1.5 \mathrm{TeV}<~{M}_{{Z}_{2}}$ at $95%$ C.L.