Specification for installing wire and cable-Henan Sanheng Cable Co.,Ltd

Specification for installing wire and cable

Jul 09,2018

For the technical specifications of wire and cable pipe and wire slot wire, the cable recruitment network has compiled the following contents for the reference of users and friends, hoping to help everyone fully understand the importance of electrical installation.

First, the main control project

1 Three-phase or single-phase AC single-core cable, not to be worn separately in steel ducts.

2 Different circuits, different voltage levels and AC and DC wires shall not be placed in the same conduit; the wires of the same AC circuit shall be placed in the same metal conduit, and the wires in the pipe shall not have connectors.

Specification for installing wire and cable

Explore the technical requirements and specifications for installing wire and cable

3 Explosion Hazardous Environment Lighting lines shall have a rated voltage of not less than 750V for wires and cables, and the wires must be worn in steel ducts.

Second, the general project

1 Before wiring the wires and cables, remove any foreign matter and water from the pipes. The nozzle shall have protective measures. After the vertical nozzle of the junction box (box) does not enter the wire or cable, the nozzle shall be sealed.

2 When using multi-phase power supply, the color selection of the wire insulation of the same building and structure should be the same, that is, the protective earth wire (PE line) should be yellow-green color, the zero line should be light blue; the phase line should be: A phase -- Yellow, B phase - green, C phase - red.

3 Line slot wire should meet the following requirements:

a, there is a certain amount of wire in the wire slot, there must be no joints. The wires are bundled according to the loop number, and the spacing of the tie points should not exceed 2m;

b. The phase and neutral lines of the same circuit are laid in the same metal trunking;

c. The lines with different anti-interference requirements of different circuits of the same power supply can be laid in the same trunking; the lines with anti-interference requirements laid in the same trunking are separated by baffles, or shielded wires are used and one end of the shielding sheath is grounded.

The common influence of the thickness of the wire and cable sheath on the quality of the wire and cable has the following two aspects.

1. Directly ring to the normal use time of wire and cable products.

In normal applications, wire and cable are often buried directly, immersed in water, or exposed to corrosive environments. If it is immersed in water for a long time or corroded by the outside world, the jacket with substandard quality will be broken down, so that the protection of the cable sheath will be lost.

2, increase the difficulty of laying wire and cable

More and more environmental requirements require high-voltage cable products to have a small outer diameter. In the process of laying, it is necessary to consider leaving a gap, so as to dissipate the heat generated after the wire and cable are energized. The thick thickness of the sheath will increase the difficulty of laying. Therefore, the thickness of the sheath is strictly in accordance with the relevant standards, otherwise it can not protect the wire and cable. Nor can we blindly pursue its thickness.

Common reasons for wire and cable sheath failure are:

Material performance defects. The material properties are not reflected by the thickness. According to the requirements of GB8815-2002, one of its indicators is not up to standard, and the flame retardant polyvinyl chloride material has an oxygen index of less than 30.

There is a problem with the cable structure. If the conductor, insulation layer, and weaving density are controlled according to the standard requirements, select the appropriate filler to make it round, and the thickness of the qualified sheath material should follow the following principles:

1. Calculate the thickness of the sheath according to the standard calculation formula: D (outer diameter before extrusion) × 0.035+1;

2. Online measurement of sheath thickness: sheath thickness = (perimeter after extrusion sheath - circumference before extrusion sheath) / 2π or sheath thickness = (perimeter after extrusion sheath - before extrusion) Perimeter) ×0.1592;

Explore the technical requirements and specifications for installing wire and cable

3, the thinnest point of single core sheath: nominal value × 85% - 0.1;

4, the most thin point of multi-core sheath: nominal value × 80% -0.2;

5. Improve the temperature of the low-density polyethylene sheathed extruder and improve the stress cracking strength. Because the extrusion temperature is too high, the plastic may be burnt or “slip” phenomenon; in addition, the shape stability of the extrusion layer is poor. , the shrinkage rate increases, and even causes discoloration of the extruded plastic layer and the occurrence of bubbles;

6. Do the extruder body and screw cooling system to eliminate friction and overheating to maintain the heat balance during the extrusion process, stabilize the extrusion pressure, promote the plastic mixing evenly, and improve the plasticizing quality.

Henan Sanheng Cable Co., Ltd , founded in 2000, It is one of the top wire and cable manufacturers in China's wire and cable industry for nearly 20 years. the company has more than 5 production lines.

The production cable can be divided into more than 50 varieties and subdivided into 1000 specifications.All products have passed national certification, such as China compulsory certification, bv certification, Nigerian SONCAP certificate, China national industrial certification, etc. China national industrial production license, etc.It also has the ability to produce products that meet international standards, such as iec, ce, rohs, etc.
If you want to buy wires and cables, you can ask the customer service staff and we will get back to you as soon as possible.