In this work we are interested in numerical calculation of the magnetic flux
density in the proximity of a three-phase underground cable circuit in horizontal
configuration by the Biot-Savart's law and comparing the levels obtained from the
field to the exposure values set by the standards. The results show that these levels
are less than the limit recommended by the standards, also this work allows to
conclude that the cables in a triangular configuration is the most preferred
configuration. The simulation results of magnetic flux density values are compared
with those obtained from software COMSOL 3.5a. A good agreement has been
obtained.