Can two wires with different cross-sections be used in parallel?
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Can a 37KW motor be powered using 16 square millimeter copper core cables, in combination with one 10 square millimeter copper core cable connected in parallel?
Using them in parallel should be fine, right?
I’m sure there’s no problem; the combined current-carrying capacity of 16 square millimeters and 10 square millimeter copper cables far exceeds the rated current of a 37 KW motor. Moreover, two wires should provide better heat dissipation than a single cable.
It is not recommended to use them in this way; differences in the impedance of each branch circuit (keep in mind that it’s not just resistance that matters) lead to uneven current distribution, which may prevent protective devices from functioning properly to protect both conductors under certain conditions. Although this approach is used in many engineering applications, since we cannot predict the actual current levels in each cable, it is still advisable to use cables with the same cross-sectional area connected in parallel
It’s possible in theory. However, it is not recommended to use it if the wire length is long.
Theoretically it’s possible, but in practice I’ve never seen it used that way.
I remember the specifications stating that parallel cables must have equal area and length (on the same path)!
No, GB 50217-2007 3.7.11 specifies specific requirements.
The calculation needs to take into account the transformer’s short-circuit impedance, the system’s short-circuit capacity, and the length of the lines. It is also related to factors such as the location where the cables are installed, the ambient temperature, and the way in which they are laid. The cable should have an appropriate cross-sectional area – neither too large nor too small. Examples of connecting conductors with different cross-sectional areas are not recommended.
We use it this way on site all the time, and nothing bad has happened; 37KW is considered a low power level. But definitely do not connect an inverter; doing so will cause problems.