Principles of Direct Matching

In case the motor starting current has a low value due to the fact that its power is relatively low or the motor starting is carried out without any load, it will reduce the duration of the starting current, attenuating the effects on the power system. The direct start of the induction electric motor consists of the starting system in which the motor receives, at its terminals, full voltage at the exact moment of departure. Therefore, the cage es5-r rotor motor should start at full load and with the chain rising approximately four to eight times the rated current, according to the type and number of poles.

Thus, the conjugate at the start can reach on average 1.5 times the nominal conjugate. This is considered to be the simplest starting method in which specific motor drive devices are not used. Only contactors, circuit breakers or switch switches are used which allow the motor to be supplied with full voltage at the moment of starting. The motors can only be started directly from the mains if they have adequate conditions and the rated capacity of the mains is sufficiently high, which can make the motor starting current irrelevant.