Abstract:

1. Execution standard GB/T 12706 Rated voltage: 1kV (Um=1.2kV) to 35kV (Um=40.5kV) Extruded insulation electrical [...]

I. Implementation Standards

GB/T 12706 Extruded insulated power cables and accessories with rated voltage ranging from 1kV (Um=1.2kV) to 35kV (Um=40.5kV) (equivalent to the international standard IEC60502)

GB/T 19666 Flame-retardant and fire-resistant wires and cables

Ii. Uses

The cross-linked polyethylene insulated power cable with a rated voltage of 0.6/1kV (irradiation) is suitable for power systems of 1kV and below. It can be used in transmission systems and distribution systems as a carrier of electricity.

Flame-retardant power cables, in addition to having the characteristics of ordinary plastic power cables, also have the features of being less likely to catch fire or the spread of fire after catching fire is limited to a certain range. They are particularly suitable for power distribution in fire emergency systems such as fire alarm, fire protection facilities, and emergency evacuation.

Halogen-free, low-smoke and flame-retardant power cables, in addition to having the characteristics of ordinary plastic power cables and ordinary flame-retardant cables, also feature no release of halogenated acid gases when the cable fires, less smoke production, less generation of corrosive gases, and good flame-retardant performance. They are particularly suitable for power distribution in fire emergency systems such as fire alarm, fire protection facilities, and emergency evacuation.

Aluminum alloy tape interlocking armored cable: It has excellent heat dissipation, good flexibility, is easy to bend, easy to peel off, and convenient for installation. The arched armor has superior side pressure dispersion performance. The inner surface of the armor is smooth and will not damage the insulation. It has good flame retardancy and is lighter than ordinary steel tape armored cables. In addition, the aluminum alloy tape itself is a non-magnetic material, and the cable will not generate eddy currents during operation.

Iii. Usage Characteristics

Ac rated voltage (U0/U) : 0.6/1kV.

2. The maximum operating temperature of silane cross-linked polyethylene insulation shall not exceed 90℃. The maximum operating temperature of irradiated cross-linked polyethylene insulation shall not exceed 105℃, 125℃ and 135℃.

3. Low ambient temperature: -15℃.

4. The temperature for cable installation and laying should not be lower than 0℃.

5. The allowable bending radius of the cable is specified in Table 1:

Table 1 Allowable Bending Radius of Cables

Project

Single-core cable

Three-core cable

Unarmored

Armor

Unarmored

Armor

The minimum bending radius of the cable during installation

20D

15D

15D

12D

The small bending radius of the cable close to the connection box and the terminal (but be carefully controlled when bending, such as using a formed guide plate)

15D

12D

12D

10D

Note: D represents the outer diameter of the cable.

6. Principle and Characteristics of Irradiation Crosslinking:

The principle of irradiation crosslinking: It uses a high-energy electron accelerator as the energy source to directly connect the polymer chains, transforming the linear structure into a three-dimensional one. Due to the high energy of the rays, they do not require crosslinking agents, nor do they need high-temperature and high-pressure conditions to cause the breaking and combination of chemical bonds, directly connecting the C-C bonds. Therefore, they have a relatively high heat resistance grade. Depending on the material formula and processing technology, they can be made into insulating materials of 90℃, 105℃, and 125℃ grades. In industrialized countries such as the United States, Japan and Europe, the usage of irradiated cross-linked insulated cables far exceeds that of warm water cross-linked insulated cables.

Compared with chemical cross-linked products, irradiation cross-linked products have the characteristics of large volume resistance, low dielectric loss and high temperature resistance grade, which greatly increases the current-carrying capacity of products of the same specification. At the same time, the performance of chemical cross-linking can also be met. Therefore, irradiation cross-linked products for low-voltage cables are ideal.

Iv. Code Name and Meaning

Table 2 Code Names and Meanings

Model

Code name

Explanation

Characteristics

ZR

NH

WDZR

Flame retardant: Classified into grades A, B and C

Fire resistance: Divided into Grade A and Grade B (not applicable to aluminum conductors)

Halogen-free, low smoke and flame retardant: Classified into grades A, B and C

Conductor

T

L

Copper (omitted)

aluminum

Insulating material

YJ

YJ(F)

Silane cross-linked polyethylene (XLPE, 3kV grade)

Irradiation cross-linked polyethylene (XLPE, 3kV grade)

Sheath material

V

Y

Polyvinyl chloride, flame-retardant polyvinyl chloride

Polyethylene, polyolefin

Shielding material

P

P1

Copper wire braided shielding

Tin-plated copper wire braided shielding

Outer protective layer

(Armor and sheath)

22

32

62

seventy-two

92

23

33

63

73

93

LS

LS02

LS03

Double steel tape armored polyvinyl chloride sheath

Fine steel wire wound armored polyvinyl chloride sheath

Double non-magnetic metal tape armored polyvinyl chloride sheath

Non-magnetic metal wire armored polyvinyl chloride sheath

Steel wire braided armored polyvinyl chloride sheath

Double steel tape armored polyolefin sheath

Fine steel wire wound armored polyolefin sheath

Double non-magnetic metal tape armored polyolefin sheath

Non-magnetic metal wire armored polyolefin sheath

Steel wire braided armored polyolefin sheath

Aluminum alloy interlocking armored with no sheath

Aluminum alloy band interlocking armored polyvinyl chloride sheath

Aluminum alloy band interlocking armored polyolefin sheath

Note: 1) Non-magnetic metal strips include stainless steel strips, aluminum or aluminum alloy strips, etc. If not specified in the order contract, the type of non-magnetic metal strip to be used shall be determined by the manufacturer.

2) Non-magnetic metal wires include stainless steel wires, copper wires or tin-plated copper wires, copper alloy wires or tin-plated copper alloy wires, aluminum or aluminum alloy wires, etc. If not specified in the order contract, the type of non-magnetic metal wire to be used shall be determined by the manufacturer.

3) If the armor of single-core cables used in AC circuits adopts a certain special structure, the current-carrying capacity of the cables will still be greatly reduced. Therefore, they should be selected with caution.