What does "50% Duty Cycle" mean?
If a compressor is turned on and running at a pressure of 10 bar. Whilst the compressor is being used the pump may not have to be on until the pressure drops to say 8 Bar. Then the compressor pump will turn on and increase the pressure till 10 bar is reached. The time the compressor is on compare to the time the compressor is urned off is the "duty cycle". So if the compressor is on as much as it is off then the duty cycle is 50%.
Jinjing compressors are not designed to run higher than a 50% duty cycle. To prevent overheating, a thermal cut out will turn the compressor off and then turn it back on when the compressor has cooled down enough to run again.