This is not my area, but could it be the high pressure cutout? Or, a thermal overload? Read the user info for troubleshooting to see what if anything, has a timer on it.
Often, you can hear the thermostat activating or see the status on the display. Is it turning on and off, or is it continuously calling for the a/c function? If the compressor is operating as the thermostat asks, it may not be the a/c unit.