How many square cables are used for the soft start of the 315 kW motor

- Jul 24, 2019-

The current of the three-phase balanced load is about 2A/KW. The rated current of the copper core power line can safely pass about 4.5-5A per square millimeter of the cross-sectional area, then the rated current of the 315KW motor should be around 630A, according to the 4.5-5A per square millimeter of electrical electricians commonly used "experience algorithm", is 630/4.5=140 square millimeters, That is to say, in the distance is not too long, can ignore the line voltage drop distance, the power supply line's intercept area, the minimum of each phase line should not be less than 140 square millimeters; You can use the specification for each phase line diameter of 95 square millimeters of power load cable (three phases four cores), the use of two cable with the same specifications in parallel laying, "corresponding and connected" wiring should be completely, so that the total cross-sectional area of 190 square millimeters per phase, the margin should be sufficient.

In addition, the capacity of the power supply control switch should not be less than 1.5---2 of the rated current, that is, the capacity of the control switch device should be between 950---1200A, other protection devices or accessories, according to the needs and requirements of the optional.