Cooler wont cool below 48 degrees.

Keep a thermometer handy. (adjust temperature control knob accordingly)
Periodically monitor temperatures inside your cooler. (adjust as necessary)
Keep the refrigerator door closed as much as possible to avoid temperature fluctuations

The temperature of the refrigerator compartment is
controlled by adjusting/setting the thermostat control
knob, located on the ceiling of the refrigerator
cabinet.
To start the refrigerator, and achieve maximum
cooling quickly;
• Turn the temperature control knob (using a coin
or screwdriver) clockwise to the furthest
(maximum) setting on the darker blue section of
the graduated control dial.
• Allow the refrigerator to run at this setting for 3~4
hours.
• When maximum cooling is achieved, turn back
the temperature control knob setting to the 2:00
o'clock position on the graduated blue control
dial.
• Correct cooling temperature is a key factor to
consider in storing and dispensing draught beer.
• Optimum temperature for serving draught beer is
between 34ºF ~ 38ºF.(1ºC ~ 3ºC)
• To maintain temperatures ranging between
34ºF ~ 38ºF.(1ºC ~ 3ºC) We recommend the
thermostat knob be positioned at the "2:00
o'clock" setting on the graduated blue control dial.
• To turn off the refrigerator, (no cooling) rotate the
control knob to the "0" position.