CNC machine tools use to install voltage regulator?

CNC machine tools need to install a voltage regulator. Why don't I say it is necessary to say that there is a need for it, because in the area of the grid output voltage stability can not be installed voltage stabilizer. But for the grid output voltage is not stable place there is a need to install a voltage regulator, because the CNC lathe CNC systems, inverters, drives these electrical components have his power supply range requirements (+-20% or so), when the external voltage is high or low 20% or so of these electrical components either produce alarms, or chaotic work. So whether you need to install a voltage regulator depends on how the voltage output of the power grid in your area, if stable, there is no need to install a voltage regulator.