A system for conditioning the three-phase alternating current electric power, including a first phase, a second phase, a third phase, and a neutral line, supplied to a load includes a plurality of first surge arresters, a plurality of second surge arresters, a plurality of third surge arresters, a three-phase surge suppressor, and a plurality of capacitors. The surge arresters minimize the amount by which the voltage between two phases and the neutral line exceeds a rated value. The three-phase surge suppressor minimizes the amount by which the voltage between the three phases and the neutral line exceeds a rated value. The capacitors minimize the amount by which the voltage between two phases falls below a rated value.