Come and take a look at the selection of motor cables
Thread Content
As shown in the attachment, which is the selection table, it seems like the choices made are rather wasteful. For example, for a 90KW motor, a 70-square-millimeter copper cable would be sufficient, or a 95-square-millimeter aluminum cable would also work fine. There doesn’t seem to be any reason for choosing a 120-square-millimeter cable as indicated in the selection table. Please have an expert give an opinion on whether there is a problem with the selection table.
How long is the cable! Don’t we need to consider line losses? Shouldn’t the design institute leave a margin?
The voltage drop of a four-core copper cable is 0.45 mV per meter; therefore, over 200 meters the voltage drop is 90 mV. As for a 400-meter length, the voltage drop should also be negligible. The margin specified here is too large
It cannot be generalized; the voltage drop during motor startup must be taken into account, as it is related to the motor’s starting current. The starting current of an electric motor is related to the motor’s rated capacity, the starting method, the system’s short-circuit capacity, the transformer’s capacity, the amount of other load connected to the transformer, as well as the specifications and length of the cables.