LED street light projects mostly are govement projects , the lighting effect represents the image of the government and city , and cost of the maintance charge is very high because of lift and aerial operation , so the quality of LED street light especially for main roads is very imporant .
What are the key features of a high quality LED street light ?
1 . Lumen effiency
As a lighting fixture , the light produce ability is very important , normally with SMD 3030 LEDs lumen effiency could reach 120-140 lumens/W , with 5050 LED is much easier to make 150-180lumens/W , with 2835 LED , should be economic version , as 1W 2835 LED would have PCT frame , the heat resistance 5050 and 3030 is better than 2835 , and LED street light with 2835 led is much harder to reach high lumen effiency .
Thermal conductivity : 5050 > 3030 > 2835
Light performance : 5050 > 3030 > 2835
Price : 5050 > 3030 > 2835
Power : 5050 1-5W , 3030 1-3W , 2835 0.5W-1W
As LED street light are outdoor lighting products , IP rate is very important , normally the LED street light have IP rate of IP65 or IP66 , IP66 is much better than IP65 .
However , while the product marketed IP65 or IP66 , the production quality control is very important , the most failure reason is the waterproof problems .
3. Driver and Warranty
The warranty period of the LED street light , normally is 2 years , 3 years and 5 years . The warranty mainly depends on the driver , minorly depends on LEDs and housing .
The first level drivers are meanwell brand , followed by philips , osram , inventronics , sosen and other china brands .
As technology developes , meanwell is not irreplacable , currently the other brands take a lot of meanwell's market share , sosen inventronics is more cost-effective while have similar quality .
There are some small factories that produce LED drivers , while have same 5 years warranty ,the price difference won't be too much .
Some economic LED street light may be made with 50W each driver , like 150W with 3PCS 50W LED driver , and 100W with 2PCS 50W driver , the 50W driver from some china driver producer may have competitive price .
4. Luminous flux maintenance factor and housing
This factor is related to the working temperature of the LEDs(while the LEDs are good quality), the working temperature of the LEDs ,while don't consider the environment temperature , the most important is the housing , PCB , thermal paste .
LEDs produce heat while working , and the PCB will transmit heat of the LEDs to the housing , the thermal paste will helps to fill the gap of the PCB and housing , to improve the cooling .
How to improve the luminous flux maintenance ?
1. Make the LEDs work at lower power , for example , 5050W work at 2W would be better than 4W , 3030 work at 0.7W would be better than 1-2W . That means use more LEDs , this will also help to improve the lumen effiency .
2. Use better thermal Conductivity aluminium PCB , at first , while the SMD LED not widely used for street lighting , copper PCB with thermal conductivity 4.0 was used to make good quality LED street light , currently as the LED quality very good and stable , mostly street LED light made with PCB have 1.0-2.0 thermal conductivity .
3. Bigger size housing while have same weightness will have better cooling , while have same weightness , bigger size will be better .
4. The up 3 points is to keep the LEDs work at low temperature , and each type LED have its safe working temperature , take the 5050 LED for example :
The safe working temperature of the LED is below 105°C , and the lower the better , while the housign , PCB make the LEDs work at lower temperature , the light decay will be lower , and the lumen performance would be better .