The LED light bar burned. What caused it?

The following picture shows the LED light strip that I have seen the most severely burned. The position from the inside of the circuit board to the external aluminum material is already black and unrecognizable. What is the cause? Then when we encounter this situation, How to deal with it? Let me explain the main reasons for the spontaneous combustion of lamps.

There are three main reasons for the self-ignition of the light bar:

The first point: low-voltage lamps are connected to high-voltage power. For this light bar, it is a low-voltage lamp 24V. The voltage we use is 220V. If the power is directly applied during installation, the internal capacitance of the lamp cannot withstand this. The voltage causes the lamp current and voltage to be too high and the circuit board is directly burned. In order to avoid this situation, everyone should pay attention to whether the product label indicated by the manufacturer on the luminaire is AC or DC. It is a high-voltage or low-voltage luminaire. If it is a high-voltage luminaire of AC220V, you can operate it directly. The low-voltage luminaire needs to be equipped with a suitable one. Its power supply can only be powered. Their working principle is to convert the input 220V voltage into 24V output, so that the low-voltage lamps can work normally.

The second point: component matching error, resistors, capacitors and other components are used to adjust the safe current of the lamp for brightness and stability. If the resistance and capacitance match on the board is wrong, it will also cause the strip to self-ignite due to excessive current. I have always said that it is important to choose the manufacturer. In the development of each luminaire, engineers must have a wealth of work experience to write the most suitable BOM meter for each product. Each lamp must be tested for normal current before leaving the factory. This will avoid burning the fixture due to component mismatches.

The third point: waterproof is not easy to enter the water short circuit, why the outdoor special light bar must be potted imported PU glue, because the waterproof performance of PU is much better than other glue, the full potting process can well prevent outdoor rain And the water vapor enters the interior of the lamp so that the circuit board and components are short-circuited by water, and the circuit board spontaneously ignites, causing the whole lamp to burn. Therefore, glue is very important, and rainwater may also be short-circuited from the gap of the waterproof plug, so it is still important to use this material.

Summarizing the basic three reasons before, we should all think hard, the selection is very important for the manufacturer of the light bar, after-sales service is very important.