How should I set up the drainage system for the air conditioner?

To drain excess water from the base pan, remove the drain cap from the back of the unit and remove the rubber plug from the bottom of the base pan. Install the drain pan over the corner of the cabinet with screws, then connect the drain hose to the outlet located at the bottom of the drain pan. You can purchase the drain hose locally to fit your particular needs, as it is not supplied.