Knowledge
Home > Knowledge > Content
How to choose the type specification of street lamp cable?
- Dec 09, 2018 -

How to choose the type specification of street lamp cable

I. general principles for the selection of electric wires and cables
In the selection of wire and cable, generally pay attention to the wire and cable model, specifications (conductor section) of the choice.
Manner selection of wire and cable types
Use, laying conditions and safety should be considered when selecting electric wires and cables. For example,
Power cables, overhead insulated cables and control cables may be selected according to different USES.
According to the different laying conditions, general plastic insulated cable, steel tape armored cable, steel wire armored cable, anti-corrosion cable, etc.
According to the safety requirements, non-flame retardant cable, flame retardant cable, halogen-free flame retardant cable, flame retardant cable, etc.
2. B. the choice of the specifications of the wire and cable
When determining the service specification of wires and cables (conductor section), the selection conditions such as heat, voltage loss, economic current density and mechanical strength should be generally considered.
According to experience, low-voltage power line because of its large load current, so the general selection of section in accordance with the heating conditions, and then check the voltage loss and mechanical strength; Low voltage lighting line because of its high requirements on the voltage level, can first allow the voltage loss condition to select the section, and then check the heating conditions and mechanical strength; For the high-voltage line, the section is selected according to the economic current density, and then the heating condition and allowable voltage loss are checked. And high - voltage overhead line, should check its mechanical strength. If you have no experience, you should consult the relevant professional units or persons. Please refer to the following table for the selection of general wire and cable specifications:
Wire and cable specifications for reference table
Conductor cross section
Mm 2 copper conductor PVC insulated cable
Ambient temperature of 25 ℃ overhead laying
IEC 01(BV) copper conductor PVC insulated power cable
The directly buried installation environment temperature 25 ℃
Vv22-0.6/1 (3+1) steel-core aluminum strand
Environmental temperature 30 ℃ aerial installation
LGJ
Allowable load capacity A capacity kW allowable load capacity A capacity kW
1.0 and 10
1.5 21 12
2.5 and 16
4, 37, 21, 38, 21
6, 48, 27, 47, 27
10, 65, 36, 65, 36
16, 91, 59, 84, 47, 97, 54
25, 120, 67, 110, 61, 124, 69
35, 147, 82, 130, 75, 150, 84
50 187, 105, 155, 89, 195, 109
70, 230, 129, 195, 109, 242, 135
95 282 158 230 125 295 165
120 324 181 260 143 335 187
150, 371, 208, 300, 161, 393, 220
185, 423, 237, 335, 187, 450, 252
240, 390, 220, 540, 302
300 435 243 630 352
1. The carrying capacity of aluminum conductor with the same specification is about 0.7 times of that of copper conductor. Aluminum conductor with the same specification is one specification larger than copper conductor.
2. The calculated capacity of this table is a three-phase 380V, Cos phi = 0.85 as a benchmark, if the single-phase 220V, Cos phi = 0.85, capacity should be * 1/3.
3. When the environment temperature is high or the surface application method is adopted, the safe carrying capacity will decline. At this time, a larger specification should be selected; When used for frequent starting motor, should choose large 2 ~ 3 specifications.
4. The PVC insulated wire in this table is calculated according to the method of single overhead laying. If it is for pipe laying or multiple laying, large 2-3 specifications should be selected.
The above data is for reference only, the final design and determination of cable model and specification should refer to the relevant professional data or electrical manual.
Second, the use of wire and cable characteristics
Please refer to the specific product catalog for the product features.
Transportation and storage of electric wires and cables
___________ transportation dropped from a height are strictly prohibited in the cable or the cable with cable, especially in lower temperature (usually 5 ℃ or so and below), throw, fall cable would likely lead to insulation, sheath craze.
2. To avoid as far as possible in the open air to open storage cable, cable disc is not allowed to make.
C. when hoisting the package, it is forbidden to load several plates at the same time. In vehicles, ships and other means of transport, cable tray should be fixed with appropriate methods to prevent each other collision or overturned, in order to prevent mechanical damage to the cable.
_____ cable shall be strictly prohibited from contact with acid, alkali and mineral oil, and shall be isolated and stored with these corrosive substances.
The cable should be rotated regularly during the custody period (3 months in summer, postponed as appropriate in other seasons). When rolling, the bottom side of the storage tray will be turned upside down, so as to avoid the bottom of the damp rot. Always pay attention to whether the cable head is intact when storing.
Pictures of cable storage period to the product factory period is limited, generally not more than a year and a half, the longest not more than two years.
Installation and construction of electric wires and cables
The design and construction of the installation and installation of electric wires and cables shall be conducted in accordance with GB 50217-94 "code for the design of electric power engineering cables" and other relevant provisions, and the necessary cable accessories (terminals and joints) shall be used. The operation quality, safety and reliability of power supply system are not only related to the quality of wires and cables, but also to the construction quality of cable accessories and lines.
Through the statistical analysis of the line fault, the fault caused by construction, installation and connection is often much more likely than the fault caused by the defects of the wire and cable body. Therefore, in order to correctly select the wire and cable and supporting accessories, in addition to the design and construction in accordance with the requirements of the specification, we should also pay attention to the following aspects:
Manner cable laying and installation should be conducted by qualified professional units or professionals, wasn't in compliance with the requirements of relevant codes and regulations construction and installation, may cause abnormal operation of the cable system.
2. B. b. human cable laying, should be a unified command and control rhythm, every 1.5 ~ 3 meters have a person on the shoulder to carry the cable, while the side to pull, slowly released.
C. when wiring mechanically, use a special cable laying machine with the necessary traction tools. C. the power to transfer should be c. the power should be evenly controlled to avoid damage to the cable.
_____ before the cable, to check the appearance of the cable and whether the head is intact, when the release of attention to the direction of the rotation of the cable disc, do not crush or scratch the cable sheath, in the winter low temperature, do not beat the way to straighten the cable, so as to avoid insulation, sheath cracking.
The cable bending radius at the time of laying should be greater than the specified value. Before and after cable laying and installation, use 1000V megohm meter to measure whether the insulation resistance between the conductors of the cable is normal, and make appropriate corrections to the measurement results according to the cable model, specification, length and ambient temperature. Small size (solid core conductor below 10mm 2) cables should also measure whether the conductor is on or off.
Pictures of cable, such as directly buried must pay attention to the soil condition, general building under the embedding depth of cable should be no less than 0.3 meters, a soft or surrounding environment more complex, such as cultivated land, building construction site or road, must have certain embedding depth (0.7 ~ 1 m), in case of accidental damage from buried cable should be erected sign when necessary.