Regarding the power consumption of LED display and the cross-sectional area of cables, this article specially organizes this knowledge. We calculate the power consumption of electrical products based on their electrical power, that is, how much "work" the electrical appliance does per hour, and this work is obtained by multiplying the current by the voltage.

  However, in actual use, the general load for power calculation is divided into two types, one is a resistive load, and the other is an inductive load. How to calculate the power consumption and cable of led display?

  Calculation formula for resistive load: P=UI , that is, power=voltage×current

  Calculation formula for inductive load: P=UIcosф, that is, power=voltage×current×power factor

  And our LED display is used by switching power supply, which is an inductive load. The power factor of its switching power supply load is cosф=0.75. Different inductive loads have different power factors. We can take the power factor cosф to 0.8 when we uniformly calculate the switching power supply of the LED display.

The driving voltage of the LED display screen is 5V, and the driving current is less than 20mA. The calculation method of the maximum power of the screen is as follows (based on 100 square meters):

 1. The specifications of the outdoor LED display screen are: the dot pitch is 10mm, the dot density is 10,000 dots/square meter, each dot (pixel) consists of 3 LED lights, 1 red, 1 green, 1 blue, and the scanning method is 1/4 scanning.

 2. Calculation of display power per square meter: P= 10000 (dots) X 3 (pieces) X 5 (volts) X 0.02 (amps) X 1/4 (scanning) = 750 (watts)

 3. The power consumption of the whole led display screen: P = 750 (watts) X100 (square meters) = 75KW

4. Power consumption of the whole screen:

 Because of the loss of products in the conversion of electric energy to each other, the general power is added 10% on the basis of the theoretical calculation value. The auxiliary equipment between the screens (air conditioners, fans, lighting, power amplifiers, etc.) also generates a certain power consumption. The power consumption of the auxiliary equipment on the screen is calculated according to the actual amount (we calculate the following formula temporarily according to 5KW).

  P=75KW+7.5KW+5KW=87.5KW

Therefore, the total power of the led display is 87500 watts, then the maximum current is:

I=P/Ucosф=87500(W)÷220*0.8(cosф)=318(A)

However, under normal working conditions, it is impossible for the light-emitting diodes of the LED display to light up for a long time at the same time, so a common coefficient formula can be used when the user's power supply capacity is small, and the common coefficient is generally 0.5. So, the above calculation should be rewritten as:

   I=P*Common coefficient/Ucosф=(82500(W)*0.5+5000(W))÷220*0.8(cosф)=168(A)

 That is to say, the total current value of this screen is 168A. Because the instantaneous current of the LED display is relatively large when starting, the three-phase 168A switch cannot be used for the main gate air switch, and the 318A air switch should be used, and 400A can be selected. Many of our fellow engineers are accustomed to directly use the number of switching power supplies on the entire screen to calculate the total power of the large screen. This method is not standard. In order to reduce costs, some manufacturers reduce the number of switching power supplies, which eventually leads to wrong power calculations.

5. Average power consumption:

  The power consumption varies depending on the playback content. For example, when playing advertising videos, the colors are rich, mostly white, and the average power consumption is 50% of the maximum power consumption; when playing simple graphics such as text, most of the screen is black, and the average power consumption is 10% of the maximum power consumption. According to normal advertising statistics, the general average power consumption is 40% of the maximum power consumption.