1. One of the 230V1650W of the double heating tube is normal, and the other tube 230V150W bursts at the terminal pins. The terminal pin inside the heating tube has melted, also the ceramic.
2. There is a black subject in the heat pipe, which should be formed by sintering the terminal pin and the aluminum pipe wall. At the same time, it is found that the aluminum melt at the bottom of the heating pipe protrudes upward. The aluminum plate at the terminal pin also shows signs of melting.
Analysis: The power of 1.230V150W is very small and the load is very low. Under normal circumstances, it will not have tube explosion and terminal pin melting.
2. When the welding time is too long and the temperature is too high, the aluminum melt at the bottom of the heating tube is prone to protrude upward, and when the terminal pin and the protruding aluminum material form a circuit to cause a short circuit, the terminal pin will melt due to high current，then burst.
Suggestions for improvement of welding: Welding parameters should be adjusted appropriately to avoid overheating and melting of the heating tube, which may cause tube explosion.