Definition and classification of wire and cable. Generalized wire and cable is also referred to as cable. The narrow sense of cable refers to the insulated cable. It can be defined as: an assembly consisting of the following parts, one or more insulated wire cores, and the coating layer, total protective layer and outer protective layer which each of them may have. The cable may also have an additional uninsulated conductor.

China's wire and cable products are divided into the following five categories according to their use: 1. Bare wire; 2. Winding wire; 3. Power cable; 4. Communication cables and communication optical cables; 5. Electrical equipment with wire and cable.

The basic structure of wire and cable:

1. Conductor: the object that conducts current, the specifications of wire and cable are expressed by the cross-section of the conductor.

2. Insulation: Outer insulation material according to its withstand voltage degree.

Working current and calculation

Electric (wire) cable working current calculation formula:

monophase

I = P present (U * cos Φ)

P- Power (W); U- voltage (220V); cosΦ- power factor (0.8); I- Phase line current (A).

Three phase

I = P present (U * 1.732 * cos Φ)

P- Power (W); U-voltage (380V); cosΦ- power factor (0.8); I- Phase line current (A).

Generally, the safe closure amount of copper wire is 5-8A/ square millimeter, and the safe closure amount of aluminum wire is 3-5A/ square millimeter.

In single-phase 220V lines, the current per 1KW power is about 4-5A, and in three-phase load balanced three-phase circuits, the current per 1KW power is about 2A.

That is to say, in a single-phase circuit, each 1 square millimeter of copper wire can withstand 1KW power load; The three-phase balance circuit can withstand 2-2.5KW of power.

But the larger the operating current of the cable, the smaller the safe current per square millimeter it can withstand.

The safe working current allowed by the cable formula: ten times five (ten times five).

A hundred times two.

Two five three five four three boundaries (two five times four, three five times three).

Two and a half times seventy and ninety-five (multiply both seventy and ninety-five lines by two and a half).

The temperature of the tube is 80% fold (changes with the temperature, multiplied by the calculated safe current number to 0.8 or 0.9).

Copper wire upgrade calculation (on the basis of the same section of aluminum core to rise one level, such as two and a half copper core is in two and a half aluminum core to rise one level, according to four square millimeter aluminum core calculation).

Add half of the bare wire (add half of the original calculated safe current)

Power cable

Suitable for AC 50HZ, rated voltage 0.6/1KV and below transmission and distribution lines, for transmission and distribution energy use. The ambient temperature is 25 ° C, and the operating temperature of the cable conductor does not exceed 70 ° C.

VV(VLV) copper (aluminum) core PVC insulated PVC sheathed power cable, suitable for laying indoors, tunnels, and trenches, can not withstand the action of external mechanical forces, can be directly buried laying.

VY(VLY) copper (aluminum) polyvinyl chloride insulated polyethylene sheathed power cable, suitable for laying indoors, in pipes, pipelines

VV22(VLV22) Copper (aluminum) core PVC insulated PVC steel tape armored PVC sheathed power vv22 cable, with VV type, can be directly buried in the soil can withstand mechanical external forces, can not withstand large tension.

VV23(VLV23) Copper (aluminum) core PVC insulated polysteel tape armoured polyethylene sheathed power cable, same VV2 type.

ZRVV22 same type VV22, suitable for flame-retardant occasions.

YJV copper core XLPE insulated PVC sheathed power cable

YJV22 Copper core XLPE insulated steel tape armoured PVC sheathed power cable

NHVV is the same as VV type, suitable for occasions with fire resistance requirements.

KVV PVC insulated control cable Uses: electrical appliances, meters, power distribution device signal transmission, control, measurement.

NH- Fire resistant power cable

ZR- Flame retardant power cable

WDZ- Low smoke halogen free power cable

Qingdao Tianxing Cable Co., Ltd. focuses on the production of customized wire and cable manufacturers, main: fire wire and cable, power cable, control cable and other products, exported to more than 40 countries and regions around the world, the annual production capacity of 1 billion yuan. 6000 square meters of storage, standing hundreds of millions of inventory, order demand for rapid distribution and delivery, large prices more favorable. Hotline: 16678668098