The timer feature might have turned off your unit when you weren't ready, if it was set accidentally. The timer can be set with the remote control or by pressing the "Timer" button on the air conditioner interface. After the "Timer" button is pressed, some units automatically set the timer for 30 minutes. The designated timer setting can be raised using the up directional button, which increases the turn-off time by 30 minutes with each press. Some units require a follow-up "Timer" button press to set the timer in motion. After the timer is activated, the unit shuts off automatically at the designated time.
If the air conditioner produces cold air and then stops, but the fan continues to run, then the desired room temperature has been reached. The thermostat determines how cold the room will become. The designated temperature is visible in the display. When the unit stops blowing cold air, the compressor turns off, but the fan continues to run to circulate the air in the room. The compressor kicks back in when the room temperature rises above the set temperature. To make the compressor stay on longer, turn the thermostat down to a lower number than room temperature. For instance, if the room temperature is 78 degrees F. and you wish the cold air to continue blowing, lower the thermostat to 74 degrees F.
When the fan fails to run but the cooler element is activated, then the unit ices over. The ice blocks the cooling element and prevents cold air from blowing into the room. It might seem like the unit has turned off, because the fan will have stopped. The ice might have been the thing that stopped the fan from turning in the first place! You can open the front grille to view the fan after the unit is turned off. Check for blockage such as trash, a plastic bag or anything else that might have been sucked in, which is preventing the fan from turning. Allow the unit to thaw before you start back up again. If the fan continues to not blow, you might benefit from contacting an technician.
An extremely dirty air filter could possibly shut off an air conditioner to prevent internal damage. When an air filter is dirty, air is unable to circulate through the unit. You can turn the unit off, remove the filter and clean it well with soapy water. Allow it to dry and reinsert it back into the unit. Turn the unit back on.