I'm sorry to tell you my experience, luckily successfully, one day I decide to sell my beloved axpert max 8kw inverter the

Model with removable display, after a few days my buyer calls me telling me that I have stayed at the oxen, I run to him and I immediately feel the smell of burning luckily some time ago I had already opened the inverter warning the seller because on his arrival I found a life out of place, however I open and see the AC input phase, disconnected from the motherboard and melted,

Italian seller solarpower and I immediately turn a disassembly card that I now attach that can be useful you have more experts, now I attach some photos sorry my translated Italian I hope you will understand

@Andry91 on face value this is the unfortunate result of what was initially a dry joint.  During the initial lifetime of the dry joint its resistance was too low to cause enough energy loss over the joint. But as heat increases so the  resistance may increase to reach that sweatspot where more heat is generated, and if that resistance is sustainable during the runaway period, the heat will cause severe damage. Until its blows open circuit. This of course is courtesy of a power chain that is designed to carry heavy currents, and as a result an input breaker or a machine inline fuse will not help.

To me this is a reminder to secure wire joints and torque them adequately.  However in this case it happened inside the machine. 

EDIT : under these circumstances one may find that there is actually nothing wrong with the rest of the machine. But the destructed joint may become a challenge to make it servicable again. 

Edited December 5, 20223 yr by BritishRacingGreen

From here comes the

Problem you can see that the screw is worn out for non-tightening

Ouch, yeah been there done something similar and had to do some major repairs because of it. I had something similar with an infinisolar-12kW-3p unit, customer took it back to the seller who didn't secure a power line to the relay board properly. This will cause sparking etc, eating away at the screw until it came loose and made contact with the PV- cable. The damage was so crazy that 3 boards needed to be completely replaced...

Moral of the story: whenever working inside something this powerful and with this much current running through it, torque tools are your friend... At very least just make sure it's as tight as you can get without stripping the screw

PS. Good job finding the issue before it got much worse, the high current can often cause fires etc like the one from my story (Pics attached)

2 hours ago, Psy said:

Ouch, yeah been there done something similar and had to do some major repairs because of it. I had something similar with an infinisolar-12kW-3p unit, customer took it back to the seller who didn't secure a power line to the relay board properly. This will cause sparking etc, eating away at the screw until it came loose and made contact with the PV- cable. The damage was so crazy that 3 boards needed to be completely replaced...

Moral of the story: whenever working inside something this powerful and with this much current running through it, torque tools are your friend... At very least just make sure it's as tight as you can get without stripping the screw

PS. Good job finding the issue before it got much worse, the high current can often cause fires etc like the one from my story (Pics attached)

Ouch🙊