Your freezer is designed to achieve lower operating temperatures so it will appear to run for longer than an adjacent refrigerator. It will run for as long as is required to achieve the correct operational conditions whilst consuming the minimum of energy during this process.
Below are a few reasons why your freezer may appear to run for longer:
Position – Is it near a heat source i.e. cooker, window, and heater or is it the time of year?
Ventilation – Is there enough air circulation around the cabinet exterior – Check the position.
The freezer must achieve -18°C to be safe. The lower the temperature, the longer the appliance will run. Try adjusting the thermostat.