Analysis to LED Street Lamps and LED Flood/Cast Light on Ultra Low Temperature Test

LED outdoor lamps especially LED Street lights and outdoor use LED Flood light lamps can or can’t work normally in cold environment is one of the quality problem which buyers need to consider. The author based on 120W LED Street lights and a 80W LED cast light lamps as the sample, to carry out this test, to verify the LED lamps in the low temperature working condition.

Objective:

1. To assess lamps can or can’t work in low temperature environment;
2. evaluate low temperature environment on the lamp component the extent of damage and if it can work after stress relief.

Test samples:

1. External power supply, One 4*30W COB light source stree Lamp
2. External power supply, One 4*20W COB light source Flood Lamp

According to the standard: refer IEC60086-2-1 2007: Part 2-1EssaiA standard.

Condition Selections: select four temperature (-20 ℃, -25 ℃, -35 ℃, -40 ℃) to evaluate, the testing time for 4 hours (2h+0.5h*4).

Testing equipment: High and low temperature Cross temperature test box.

Sample Treatment methods: Put Two types of lamps with power supply into the test box, lamp plug through indwelling hole on the test box and connected the city electricity supply outside, and seal the indwelling hole with rubber stoppers.

Test process:

1. When lighting them at room temperature ,can normal work.
2. The lamp is placed in the test chamber, at low temperature -20 ℃ they run 2 hours, see whether the lamps can normally work.
3. The temperature dropped to -25 ℃ then run 0.5 hours, see whether the lamps can normally work.
4. The temperature dropped to -35 ℃ then run 0.5 hours, see whether the lamps can normally work.
5. The temperature dropped to -40 ℃ then run 0.5 hours, see whether the lamps can normally work.
6. The temperature is raised to -35 ℃ then run 0.5 hours, see whether the lamps can normally work.

The test results:

When the Two lamps at room temperature, -20 ℃, -25 ℃, -35 ℃,they can be normally lighted; dropped to -40 ℃, two lamps are not lit; and then back to -35 ℃, two lamps can light again.

Test conclusion: the lowest temperature the two LED lamps tolerate can reach -33 ℃ but not to -40 ℃,. (Note: the preferred temperature on IEC60086-2-1 standard list is -40 ℃, -33 ℃, -25 ℃, -20 ℃, although the actual test temperature is -35 ℃, but the judge result is as to -33 ℃.)