At what capacity do motors require reduced-voltage starting? Could you provide examples from work and the calculation process?
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High-power motors require reduced voltage for starting, but how can this be determined? Generally, there is no fixed rule specifying what size of motor requires reduced-voltage starting; rather, it depends on how much current the bus system to which the motor is connected can handle. Other factors to consider include the capacity of the transformer, the distance between the motor and the transformer, the cross-sectional area of the wires, and the impact of the starting current on the power grid. Generally, when the capacity of the motor exceeds 5-10% of the transformer’s capacity, reduced-voltage starting is required. Although the statement is correct, how exactly should it be calculated in practice? I hope fellow sailors can provide answers using their own experiences. Thank you!
An understanding from a non-specialist perspective, for reference only. Every electrical device has its maximum allowable current. The greater this current, the larger the capacity of the power supply facilities involved will be. From this perspective, can a starting point for design be found? For reference.