If this is your compressor problem here are a few things to look for and perhaps fix if your compressor reset button always trips.
First off, what are we talking about when we are speaking of the compressor reset button? You might know it as the thermal cut out or thermal safety switch. Others know it as the reset button. You can see one of them on the end of the electric motor in the image below.
It may be a small red button on the shroud of the compressor, it may be a button on the end of the motor if that is visible on your compressor, and I have seen them on the side of the motor at the shaft end, on some compressor motors.
Regardless of where the compressor thermal reset button is on your compressor - on the motor or on the shroud of the compressor - it's purpose is to cut the power to the motor in the event that the motor itself gets too hot. Without the thermal reset button if there were a condition in the motor that was causing it to get hot, eventually the heat itself would destroy the compressor motor.
If the compressor reset button always trips on your compressor, the motor is getting too hot!
The power cord of the compressor is sized to allow sufficient power to the compressor motor. Restricting it through a smaller wire will cause the motor to over heat. If the motor overheats, the thermal cut out will shut it down.
Older air compressors - and some not so old if the compressor has tipped over for some reason - can develop a tank check valve leak. If that happens, air will be bleeding out of the tank all the time, even when the compressor is running. If that is happening on your air compressor, it will take much longer for the tank to fill - if it ever does - to cut out, and the by product of that is a motor that overheats.
See the troubleshooting pages on this site about how to fix a leaking tank check valve.
If your air compressor has or is developing a mechanical issue - perhaps a weakened or broken valve or a blown gasket in the pump, the compressor may have to run much longer than normal to fill the tank to cut out. It may run so long that the motor will shut down on thermal cutout before the tank is full. If you air compressor seems to be undergoing this scenario, it may be time to add a valve and gasket kit. The troubleshooting pages on this site address these issues.
If you continue to have problems with your compressor reset button always tripping off, visit the troubleshooting forum page to post your compressor problem. Thousands of folks visit this site weekly, and compressor troubleshooting help will be offered, typically in a very short while.