Shigatse kvvp shielded control cable 2*1.0 square spot
Shigatse kvvp shielded control cable 2*1.0 square spot
update time: 16:57:30 information source: Jiaming
Shigatse kvvp shielded control cable 2*1.0 square spot
first, according to the transformer capacity and connection method, usually 0.4kV is Y-connected, and according to the capacity of 630 and 400, the low-voltage output rated current is 909a and 577a; This current can be selected as the long-term working current; Of course, it can also be selected by ig= ∑ igt+k* ∑ IDT (see Chapter 7 of the power design manual for details), that is, according to long-term load and short-term load; Now you can start to calculate the cable section, k*ixu "Ig; Ixu is the allowable current carrying capacity of the cable, Ig is the long-term allowable working current, which can be selected according to capacity or load; For the sake of insurance, choose only large or small according to the rated capacity; K is the correction coefficient under different cable laying conditions, which is divided into single cable in the air, multiple cables in the air, through pipe in the air, single cable in the soil and multiple cables in the soil; See the attached table in Chapter 17 of the design manual for the coefficient, which contains many contents; According to ixu=ig/k, the current carrying capacity can be calculated, and the cable can be selected according to the current carrying capacity; For example 909a, multiple cables are laid in the air, the average temperature of the environment * * * is 35 degrees, the allowable working temperature of the cable * * * is 65 degrees, and the spacing is the outer diameter of a single wire; Check the manual k=0.865*0.9=0.7785, ixu=909/0.7785=1168a; 1168/2=584a; Check the current carrying capacity of cables. The current carrying capacity of cables laid in the air of 300 section is 636a, and 2 cables are used, which is greater than 584; So two can be used together! In addition, 400KVA, the average temperature of the environment * * * is 35 degrees, and the allowable cable working temperature * * * is 65 degrees, 577/0.865=667a, and the 300 section is not satisfied; So we need to look at our own environment. The environment assumed here may not be in line with the actual needs
according to my understanding, there are many manufacturers of mining electric drill cables to meet the bonding requirements of structural parts in seismic or despicable working conditions. Among so many manufacturers, some are very formal, some are not formal, their product quality is still very poor, and the after-sales service is not good. If you choose such manufacturers → standard strand, indented strand The products of compact strand, epoxy resin steel strand and PC strand will not only make you want to win more successful use, but also cause adverse effects on your physical health due to improper use. Therefore, when choosing, we should understand the market situation of the product, understand the evaluation of consumers on different brand products, and choose according to what we know, so that the selected products can better achieve the satisfactory use effect. In fact, although there are so many irregular manufacturers, it is relatively easy to choose high-quality mining electric drill cables if we can pay attention to them. Finally, I hope that you can pay attention to and be vigilant when choosing to ensure that the quality of the products you choose is qualified
the molecular structure of the material changes from linear to three-dimensional molecular structure, and the temperature resistance grade is increased from non crosslinked 70 ℃ to 90 ℃, 105 ℃, 125 ℃, 135 ℃, or even 150 ℃, which is% higher than the ampacity of cables of the same specification. High insulation resistance; Because the irradiation crosslinked power cable avoids using hydroxide as a flame retardant, it prevents the pre crosslinking and the decline of the anti-interference ability of the insulation resistance due to the absorption of moisture in the air by the insulation layer. Thus, the insulation resistance value is guaranteed. Long service life and strong overload capacity; Due to the high temperature resistance and high aging temperature of polyolefin materials after irradiation crosslinking, the service life of power cables with cyclic heating during use is extended. Environmental protection and safety; As the materials used for power cables are halogen-free environmental protection materials, the combustion characteristics of cables meet the environmental protection requirements. Product quality temperature; The quality of traditional warm water crosslinked power cable is affected by water temperature, agent preparation process, crosslinking additives and other factors
The value ofis very small and can generally be ignored. According to the fault resistance and breakdown gap, cable faults can be divided into open circuit, low resistance, high resistance and flashover faults, as shown in Table 1. Table 1 Classification and description of cable fault nature: Z0 in the table is the wave impedance value of cable, and the wave impedance of power cable is generally ω between. The purpose of the above classification is also to facilitate the selection of test methods. According to the current popular fault location technology, open circuit and low resistance faults can be tested by low-voltage pulse reflection method, high resistance faults should be tested by impulse flashover method, and flashover faults can be tested by DC flashover method. Field personnel have RF
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