Power cables are generally divided into single-core, double-core and three-core cables. The single-core cable means that there is only one conductor in one insulating layer, while the double-core cable means that there are two conductors in one insulating layer. So is single-core cable better or twin-core cable better?

The difference between single-core cable and multi-core cable

1) 2-core cable: When the neutral line of 1kv and the following switching power supply is immediately grounded, the number of cable cores in the single-phase electric control circuit, when the maintenance line and the neutral point share the same electrical conductor, the 2-core cable should be selected. The control loop of the DC power supply system can be used, and a 2-core cable should be used.

2) 3-core cable: 1kv and the following switching power supply neutral line is immediately grounded, the number of cable cores of the single-phase electric control circuit is: when the maintenance line and the neutral point are separate, the 3-core cable should be selected.

3) 4-core cable: 1kv and the following 4-core cable (3+1 cable), in which the fourth core is not only used for grounding protection but also the transportation power supply system is not balanced current volume and short-circuit capacity. Its size is determined by the amount of unbalanced current and short-circuit capacity, but generally not less than 1/2 of the phase line.

4) 5-core cable: 1kv and the following three-phase four-wire power distribution room system software, some electrical equipment power distribution equipment routes with a higher safety factor, and some of them must not only ensure the safety of electricity use, but also anti-interference For the communication management center and automatic machinery of the neutral grounding device, the TN-C power distribution room system software with 5 copper-core cables should be selected, so that the maintenance line (PE line) and the neutral point (PN line) are separate, and the cross-section of the cable core is normal. 3 large 2 small or 4 large 1 small or 5 large.

5) The difference between the 4-core cable and the 3+1-core cable: 1kv and the following three-phase four-wire power distribution room system software, when the maintenance line and the neutral point share the same electrical conductor, the 4-core cable should be selected. Instead of using a 3-core cable plus a single-core cable to form a loop, or even immediately using the metal sheath of the 3-core cable or the armored cable layer as a neutral point. Otherwise, when the 3-phase current is unbalanced, it is equivalent to the operation of a single-core cable, and it is very easy to cause DC influence.

Which is better, uniaxial cable or twinaxial cable?

1. From the current point of view, the current passing through the multi-core cable with the same cross-sectional area is relatively larger than the single-core current, and the load is larger.

2. From the point of view of electrical loss, both ends of a single-core cable are directly grounded. The metal shielding layer of the cable may also generate a circulating current that can reach the current carrying capacity of the cable, and waste electrical energy to cause loss. Multi-core cables are generally three-core cables. Since the sum of the currents flowing through the three cores is zero during the operation of the cable, there is essentially no induced voltage across the metal shield of the cable.

3. From the point of view of cost, among the wires of the same cross-sectional area, the cost of single-core cables is cheaper than that of multi-core cables, and the multi-core cables are slightly more expensive.

4. From the installation point of view, the single-core wire appears hard when passing through the tube, while the multi-core wire is softer and easier to wire.