The difference between low voltage cable and high voltage cable

Here are many kinds of cables, but the most basic can be divided into low-voltage cables and high-voltage cables, but how to distinguish the two? Some people say it’s 250V, and some say it’s 1000V. How do you distinguish high voltage and low pressure?

According to China’s industry standards, electrical equipment is divided into high voltage and low voltage: high voltage: equipment with voltage above 250V to ground; low voltage: equipment with voltage above 250V to ground. According to the 2009 power line safety regulations, electrical work is divided into high voltage and low voltage

High voltage electrical equipment: voltage level is 1000V and above; low voltage electrical equipment: voltage level is below 1000V;

Generally, high voltage line refers to 3 ~ 10kV line; low voltage line refers to 220 / 380 V line.

The method to distinguish the voltage of high voltage wire by naked eyes is as follows:

1. Know the voltage level.

In China’s power industry, the common voltage levels are 220 V, 380 V, 1000 V, 10000 V, 35 000 V, 110 000 V, 220 000 V, 500 000 V, etc. Generally speaking, 220 V and 380 V are considered as low voltage, mainly for household electricity; and above 35000 V are high voltage, mainly used for power transmission. Between the two is medium pressure. It must be pointed out that touching high-voltage wires or carrying out live work under the line has great danger.

2. Identify low voltage lines.

The outdoor low voltage line has several obvious characteristics

1) Generally, the cement pole is not more than 5 meters.

2) The thickness of wires is the same, and the number of wires is multiple of 4. This is because low-voltage wires generally adopt three-phase four wire system. If these characteristics are available, it can be determined that the line voltage of the wire is 380 V and the phase voltage is 220 v. (phase voltage is line to ground voltage, line voltage is voltage between two lines)

3. Identify medium and high voltage lines.

Medium and high voltage lines also have obvious characteristics

1) If the thickness of the wires is the same, the number of wires is a multiple of 3. This is because the transmission lines generally use three-phase transmission. If these characteristics are available, it can be basically determined that the wire is 10000 volts.

2) If the thickness of the wire is different, the number of thick lines is a multiple of 3, and there are only two thin wires, which are assumed to be at the highest position. This is because the thin wire is not used for power transmission, but for lightning protection, also known as lightning conductor. If these characteristics are available, it can be determined that the wire is a high-voltage line.

4. Further identify the high voltage line.

In order to improve the transmission capacity, high-voltage wires generally use split conductors. Generally speaking, one wire is used for one phase. Now several wire bundles are used to replace the original one. Knowing this, it is easy to judge the voltage level of the wire. 1) One phase with one wire is 110000 volts; 2) one phase with two wires is 220000 volts; 3) one phase with four wires is 500000 volts.

In our daily contact with high-voltage lines, but in the face of medium and low-voltage lines, we still have to be careful. Every year, countless people die of electric shock, so no matter what kind of cable is used, we must use the national standard cable with quality assurance. In order to improve the quality of the products, the products are produced in strict accordance with the national standards (GB / JB) and the International Electrotechnical Commission (IEC). The enterprise has passed the ISO9001:2008 international standard certification, obtained the national industrial product production license and the China National Compulsory Product Certification (CCC certificate). Among them, the production technology of XLPE cable is in the forefront of the industry, In order to closely follow the construction of the State Grid, the company also purchased advanced 35kV cross-linked cable production line, one-step silane cross-linked production line and other advanced wire and cable production lines. No matter what kind of cable, Zhujiang cable will always give you the best quality!

Post time: Nov-10-2020