APCE
/
/
/
Ren Yi Electric Encyclopedia: The relationship between the square of the wire and the current

Ren Yi Electric Encyclopedia: The relationship between the square of the wire and the current

  • Time:2020-07-07 15:54
  • Visits:

(Summary description)1. Calculation of conductor cross-sectional area and current carrying capacity:

Ren Yi Electric Encyclopedia: The relationship between the square of the wire and the current

(Summary description)1. Calculation of conductor cross-sectional area and current carrying capacity:

  • Categories:Industry News
  • Author:Ren Yi
  • Origin:http://www.scrydq.com
  • Time of issue:2020-07-07 15:54
  • Views:
Information
1. Calculation of conductor cross-sectional area and current carrying capacity:
 
Generally, the safe current carrying capacity of the copper wire is determined according to the maximum allowable core temperature, cooling conditions, and laying conditions.
 
Generally, the safe current carrying capacity of copper wire is 5-8A/mm2, and that of aluminum wire is 3-5A/mm2.
 
Calculate the upper and lower ranges of the cross-sectional area S of the copper wire:
 
0.125 I(mm2) <S= I /(5~8)< 0.2 I(mm2)
 
S---Copper wire cross-sectional area (mm2) I---Load current (A)
 
The recommended value of the safe current carrying capacity of 2.5mm2 BVV copper wire 2.5×8A/mm2=20A 220V×20A= 4400W 4mm2
 
Recommended value of safe current carrying capacity of BVV copper wire 4×8A/mm2=32A 220V×32A= 7040W 6mm2
 
 
 
 
 
The recommended value of the safe current-carrying capacity of BVV copper wire 6×8A/mm2=48A 220V×48A=10560W
 
2. The relationship between wire square and current-copper wire safety calculation method
 
The maximum current that the national standard 1 square wire can withstand is 19 amperes, but it needs to be considered according to the use environment, temperature, and installation method. The roughest estimation method is 5A for single-phase 1000W and 2A for three-phase current. The general copper wire safety calculation method is:
 
 
 
 
 
If it is aluminum wire, the wire diameter should be 1.5-2 times that of copper wire.
 
The safe current carrying capacity of the 2.5 square millimeter copper power cord-28A.
 
Power 220×28=6160W The safe current carrying capacity of 4 square millimeter copper power cord-35A.
 
Power 220×35=7700W The safe current carrying capacity of 6 square millimeter copper power cord-48A.
 
Power 220×48=10560W The safe current carrying capacity of 10 square millimeter copper power cord-65A.
 
Power 220×65=14300W, the safe current carrying capacity of 16 square millimeter copper power cord-91A.
 
The safe current carrying capacity of 25 square millimeter copper power cord-120A.
 
The power calculation general load (can also be used as electrical appliances, such as lighting, refrigerator, etc.) is divided into two types: one type of resistive load, the other is inductive load. Calculation formula for resistive load: P=UI
 
The calculation formula for fluorescent lamp load: P=UIcosф, where the power factor of fluorescent lamp load cosф=0.5. Different inductive loads have different power factors. When calculating household appliances in a unified manner, the power factor cosф can be taken as 0.8.
 
The total power of all electrical appliances in a family is 6000 watts, and the maximum current is I=P/Ucosф=6000/(220×0.8)=34(A).
 
Under normal circumstances, home appliances cannot be used at the same time, so add a common coefficient, which is generally 0.5.
 
So the above calculation should be rewritten as I=P*common coefficient/Ucosф=6000*0.5/220*0.8=17(A), the total current value of this family is 17A.
 
The main brake air switch should be greater than 17A. The above is not accurate. For example, the total power is 10,000 watts (the maximum power is 6000 watts), and the 5000 watts total brake is not enough according to the public coefficient, and the maximum power plus 0.5 of the remaining power should be taken.
 
Sichuan Renyi Electric Co., Ltd. is registered under the name of Ren Yi, a senior technician for substation maintenance, and uses scientific research, knowledge innovation, publicity, promotion, and teaching that the temperature of electrical contacts (connectors) is lower than the temperature of its conductors (wires). The theory and technology of "thermal electrical contacts" produces and sells electrical equipment with registered trademarks that do not overheat electrical contacts (joints). Patented products are integrated.
Today

Today talks about: Solving various electrical disasters from the source of electricity -

Mount Everest on Electricity [Today's Talk]: The difference between "heating" and "overheating"; the three stages of "Electrical Contact Overheating":
2019-11-18
119

119 Safety and firefighting must be done practically. "Superconductivity" cannot solve man-made disasters such as electrical fires!

119 Safety and firefighting must be done practically. "Superconductivity" cannot solve man-made disasters such as electrical fires!
2019-11-09
Pay

Pay special attention to the power safety revolution forum, and Mount Everest discusses electricity-to solve the mystery of a century of electrical disasters in the world of man-made disasters! Solve and eradicate the global ...

Pay special attention to the power safety revolution forum, Mount Everest on electricity-to solve the mystery of a century of electrical disasters and man-made disasters in the world! Solve and eradicate the global problems of air disasters, fires and spontaneous combustion from the source of electricity! Look at the Tianbang in Nanchong and Niuhuang Wan in Chengdu, one of China's ribs. In decades of production practice, how to continuously explore, repeatedly test, reverse thinking, gradually improve, and independently innovative scientific and technological achievements. This intellectual property, which is unique to China in the world, is completely independent, and is sent to the country free of charge. Take a look at the folk "Lao Lai Le", defying academic authority, summoning conscience, calling for revolution, and creating a unique world, how to overcome electrical disasters and man-made disasters, this worldwide problem! Special reminder: This is just advice and advice, not an advertisement. If you believe in an advertisement, or listen to advice and advice, it's up to you. This is a matter of folk merit. Advice and advice do not ask for compensation, do not ask for likes, do not want to be Internet celebrities, improper celebrities, just because of professional responsibility, just because I see someone killed by an electrical disaster, my conscience is also disturbed. WeChat friends, and their respective media think this is positive energy and a good thing. You can be busy reprinting and disseminating the original text (the original propaganda and promotion are not for profit, and I am responsible for mistakes). If the national media wants to propagate and disseminate, first declare: this is not advertising! Without money, who can do it?
2019-11-08
Special

Special attention should be paid to national power safety in summer

History, tradition, and habit believe that: poor contact; weak electrical contacts (joints); electrical contacts whose temperature is higher than (exceeds) the temperature of its conductor (line). The theoretical concept of "electrical contacts overheating" is wrong! It is believed that oxidative corrosion (chemical, electrical corrosion) caused the "electrical contact overheating", which reverses the causality! Please go to the China Renyi Electric Platform (challenge) for academic discussion and debate!
2015-07-23

CONTACT US

 

Email: 577538063@qq.com

Phone:+86 13438175710

ADD

 

128 Hongyang East Road, Qingbaijiang District, Chengdu

CHENGDU BRANCH

 

Room 3101, Tower 2, Raffles City, Wuhou

District, Chengdu,PR China

+86 13438175710
577538063@qq.com

 Copyright © 2022 Sichuan Renyi Electric Co., Ltd. 蜀ICP备12025125号  Powered by:www.300.cn   SEO