It is important to stress that the maximum temperature supported by the insulating components of the electric machines is properly indicated so that it is capable of operating in an environment that presents a temperature of approximately 40ºC. It is extremely important to thoroughly check the ambient temperature control so that it can not exceed the values for which the engine was designed. It can be said that the thermal equilibrium of an engine can be modified as soon as the supply voltage varies. A voltage drop determines the flux of the magnetic circuit, thereby reducing the losses in the iron and the current in a vacuum.
Therefore, it is important that the motor torque can overcome the resistant torque to prevent excessive slippage. Considering that the motor tapered roller bearings torque is the result of the product between the flux and the intensity of the absorbed current, in case the flux decreases, the current intensity automatically increases. With the load current raised by the voltage drop, the motor can heat up, increasing the losses. A supply voltage rise may have more limited effects, considering that the no-load current increases at the same time as the on-load current decreases.