I have tightened all the bolts in the panel. The bolts holding the breaker to the panel, the cooper wire going into the breaker and the cooper wire going into the outlet. All have been tightened but the problem is still present. Today the outside temps have reached 50f and inside the container its also 50f. Inlet and out let are below 75 for all these miners. But they still stop mining. They are breaking after mining for 20-30 minutes.
The reason why I asked if these "bad" miners were located in the same area is simply to help you troubleshoot further, now that you answered, it's actually good news, at least we know there is a good chance that the problem isn't the miners themselves, to confirm this you have to take 1-2 two miners and put them elsewhere, see if they act any differently.
You should also try to reduce the fan speed on some of these miners to see if they would run any longer/better, if so happen that this rack directly faces the intake fans or has a small difference in reference to the airflow they can still can weird, I would also check the PSU screws and make sure all hash boards are tightened, I would connect the bad miners to a different switch using different cables, I would also use different power cords.
Also in regards to checking the breaker and the wires, you need to check the voltage right before the miners stop hashing, if the wire is damaged it can cause a voltage drop, and these gears don't do well with low voltage, so what could be happening is that after loading the wire for 20-30 mins it gets warm, voltage drops, the PSU goes into protection mode and stops feeding the hash boards.
I was thinking that maybe the psu is overheating? It feel warm but not hot. The very back of the psu next to the miners exhaust fans is probably hot? The idea I have is that maybe they are getting to warm and shutting down? I have a half inch space between the miners to allow some warm air to come back into the conex. Its only half and inch and seems like nothing. Could this be causing the problems? Maybe these psu's are sensitive to heat and shut down? I have set up a test scenario with some of my miners. I moved some to a different location and I made some have zero space between them. Next time temps are 50+ I will know if these miners have the same problem. If anyone know anything about the S19 psu shutting down because of heat. Please leave some info. Thanks.