If your De'Longhi portable air conditioner keeps shutting off, there are a few possible explanations. The most common reason is that the unit is overheating and has a built-in safety feature that kicks in to prevent damage. Other potential reasons include a clogged filter or faulty coolant levels.
If your unit is shutting off due to overheating, the first thing you'll want to do is make sure it's properly ventilated. Check the exhaust hose to ensure it's not kinked or blocked, and clear any debris from around the unit itself. If you're using the air conditioner in a small space, try opening a window or door to improve airflow. You may also want to try raising the temperature setting on the unit; a lower temperature setting will cause the unit to run for longer periods of time, which can lead to overworking and eventual shutdown.
If your AC unit has a clogged filter, this can also cause it to overheat and shut down. Be sure to check the filter regularly (according to manufacturer's instructions) and clean or replace it as needed. A dirty filter not only reduces efficiency but can also block airflow and cause problems like this one.
It's also possible that your De'Longhi portable air conditioner isn't receiving enough power from its current outlet/extension cord setup. Make sure the cord is plugged in securely and that you're using an appropriate extension cord for outdoor use (if necessary). If none of these troubleshooting tips solve your issue, contact customer service for further assistance.