Checking steps: There is mains power connected to the outdoor unit, the frequency conversion board is not powered on, and there is no indicator flashing. After inspection, it was found that the 220V fuse was broken, and the problem of the device itself was ruled out. The biggest cause was a serious short circuit in the load. Follow the vines and check the breakdown of the 300V rectifier bridge, indicating that there is still a serious short circuit in the rear stage. wear, the fast recovery diode burst, and the surrounding resistance devices and switching power supply are normal.
Fault analysis: It is caused by IGBT overcurrent or its own aging, which leads to the breakdown of the fast recovery diode, and the entire +B circuit is short-circuited instantly, causing breakdown of the bridge pile and fuse of the fuse.
Troubleshooting: A certain treasure bought a three-piece set, and the trouble was eliminated after replacement.
