1, the first question, to answer you like this: I can only tell you that ten fingers are different. Therefore, it is not uncommon for the same batch of inverters to be scrapped after ten years of use.

2. With the increase of the service life of the inverter, the internal devices of the inverter will also change, just like people, they will go through youth, middle age and old age. Therefore, it is normal to appear now.

3, the manufacturer's suggestion is correct, because there is leakage current in the inverter itself, which is an indisputable fact. The inverter itself has the function of current protection. If the leakage protection is installed, it can be said that the function is duplicated. This is my understanding. Welcome the great god!

4, you think too much, just the action of the leakage protector, basically has nothing to do with the quality of the inverter, feel free to use it.