The resulting low voltage long-term rise in temperature motor windings leads to a rapid aging of insulation and, consequently, to reduced service life. Overvoltage network power consumption and heat buildup in the windings of the motor also increases. When measured at the motor terminals voltage fluctuations within +6 / -10% from that specified in the nameplate nominal value, you can expect the design life of the motor. This will happen if current consumption is less than indicated on the nameplate value at full load, the motor is sufficiently cooled and does not cause any surges or asymmetry. In cases where differences over the permissible limits of short duration, also should not expect a significant reduction in the life of the motor, unless the value of the peaks are not so large that it would raise short- circuit in the stator windings. However, for permanent or long-term voltage fluctuations over +6 / -10% should choose an electric motor for industrial use will ensure an acceptable service life and efficiency.
For example, for particularly complex cases, leading companies are developing a special series of electric motors for industrial use (usually ranging from 2.2 to 22 kW) with high efficiency. For example, these motors are used in serial submersible pumps grundfos, which are successfully applied in various regions of Russia. Thus, in the Log, Sverdlovsk area pumps SP-125, equipped with scp, provide water to the city and surrounding villages and the plant. When that power surges are not uncommon, the equipment worked without problems and will reduce power consumption by 15%.