Detection of Damper Motor Mechanically Disconnected from Damper Assembly

A method of testing a HVAC unit for a disconnected damper motor, the method comprising:

• closing an outside air section of a damper assembly of a HVAC unit;
• circulating air through the HVAC unit;
• comparing a discharge air temperature to a return air temperature;
• if the discharge air temperature is not substantially equal to the return air temperature, determining a damper motor is disconnected from the damper assembly;
• and
• if the discharge air temperature is substantially equal to the return air temperature:
• recording a first absolute value, the first absolute value comprising a difference between a first comparison discharge air temperature and a first comparison outside air temperature;
• starting an economizing function of a controller of the HVAC unit, the economizing function comprising a free cooling target temperature;
• comparing the first absolute value to a second absolute value, the second absolute value comprising a difference between a second comparison discharge air temperature and a second comparison outside air temperature;
• and
• if the first absolute value is not greater than the second absolute value, determining the damper motor is disconnected from the damper assembly.