Cable selection
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This post was last edited by olala-1 on 2010-11-15 at 14:59. I need to choose cables for a factory laboratory, but I’ve never done this kind of work before. There are 5 motors in total, as well as 2 sets of heaters that need to be powered. All of them require a 3-phase 380V power supply. I should first calculate the maximum current for each device, add those values together, and then select a cable specification based on that total, right? Can I consider the current rating listed on the cable samples as the line current?
The current-carrying capacity of the cable should be more than 1.5 times the current of the electrical load.
This post was last edited by zhaohh3211 on 2010-11-16 at 16:02. Please, someone who knows more help me – is my algorithm correct or not?
This post was last edited by zhaohh3211 on 2010-11-16 at 16:17. W=sqr(3)×U×I×cosΦ; using this formula gives the line current. The line currents are then added together to obtain the total load current. An additional factor of 1.5 is applied as a basis, and then a cable from the cable catalog is selected that has a rating equal to or greater than this value. Is that how it works?
This post was last edited by zhaohh3211 on 2010-11-16 at 17:10. If the U you use is line voltage, then the I you obtain is line current； If U used is the phase voltage, then the I you obtain is the phase current. When choosing a cable, it should be one grade higher, right?