When the neutral point of the power supply of 1kV and below is directly grounded, the number of cable cores of the three-phase loop should meet the following requirements:

1.When the protective wire is connected to the exposed conductive part of the powered equipment and grounded, the following requirements shall be met:

  1. When the protection line and the neutral line share the same conductor, a four-core cable should be used.
  2. When the protection line and the neutral line are independent, a five-core cable should be used; when it meets the requirements of Article 5.1.16 of this code, a four-core cable can also be used

The cable is composed of another protective wire conductor.

2. When the grounding of the exposed conductive parts of the power receiving equipment is independent of the grounding of the power system, a four-core cable should be used.

How to Determine Power Cables Core Numbers

When the neutral point of the power supply of 1kV and below is directly grounded, the selection of the number of cores of the single-phase cable should meet the following requirements:

1 When the protective wire is connected to the exposed conductive part of the powered equipment and grounded, the following requirements shall be met:

  1. When the protection line and the neutral line share the same conductor, a two-core cable should be used.
  2. When the protection line and the neutral line are independent, a three-core cable should be used; when it meets the requirements of Article 5.1.16 of this code, a two-core cable can also be used.

The core cable is composed of another protective conductor.

2 When the grounding of the exposed conductive parts of the power receiving equipment is independent of the grounding of the power system, a two-core cable should be used.

How to Determine Power Cable Core Numbers

The selection of the number of cable cores for the 3-phase power supply loop of 3~35kV shall meet the following requirements:

  1. When circuits with larger working currents or cables are laid underwater, 3 single-core cables can be used each time.
  2. In addition to the above cases, a three-core cable should be used; the three-core cable can be an ordinary turnkey type, or a 3 single-core cable twisted structure type.

110kV three-phase power supply circuit, except for laying in lakes, under the sea and other places and the cable cross-section is not large, the three-core type can be used every time.

3 single-core cables.

For three-phase power supply circuits above 110kV, 3 single-core cables are used for each response.

For high-voltage AC single-phase power supply circuits such as electrified railways, two-core cables or two single-core cables should be used each time.

The selection of the number of cable cores of the DC power supply loop shall meet the following requirements:

  1. For low-voltage DC power supply circuits, two-core cables should be used; single-core cables can also be used.
  2. Single-core cables should be used for HVDC transmission systems; coaxial two-core cables can also be used when laying underwater in lakes or seas.

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