The number of cores of power cables can be divided into single core, two cores, three cores, four cores, and more than five cores according to the number of cores. So how to choose the number of cores in engineering applications depends on the specific analysis of the appropriate situation. The editor summarized it and divided it into the following categories.

1. This type means that when the neutral point of the power supply of 1kV and below is directly grounded, the selection of the number of cable cores in the three-phase circuit should comply with the following regulations:

When the protective wire is connected to the exposed conductive parts of the powered equipment and is grounded:

(1) When the protective line and the neutral line are independent, a five-core cable should be used; when the provisions of Article 3 of this specification are met, a four-core cable and an additional protective line conductor can also be used.

(2) When the protective wire and neutral wire share the same conductor, a four-core cable should be used.

When the grounding of the exposed conductive parts of the powered equipment and the grounding of the power system are independent of each other, a four-core cable should be used.

2. When the neutral point of the power supply of 1kV and below is directly grounded, the selection of the number of cable cores for the single-phase circuit should comply with the following regulations:

When the protective wire is connected to the exposed conductive parts of the powered equipment and is grounded:

(1) When the protective wire and neutral wire share the same conductor, a two-core cable should be used.

(2) When the protective line and the neutral line are independent, a three-core cable should be used; two-core cables can also be used if the provisions of Article 3 of this specification are met.