Detection of Damper Motor Mechanically Disconnected from Damper Assembly

摘要

In an embodiment, a method of testing a HVAC unit for a disconnected damper motor is provided. An outside air section of a damper assembly is closed and air is circulated through the unit. If a discharge air temperature is not substantially equal to a return air temperature, the damper motor is determined to be disconnected. Otherwise, an economizing function having a free cooling target temperature is started. An outside air temperature is compared to the free cooling target temperature. If the outside air temperature is less than the free cooling target temperature, the damper motor is determined to be disconnected if the damper motor has been commanded to fully open the outside air section. If the outside air temperature is not less than the free cooling target temperature, the damper motor is determined to be disconnected if a discharge air temperature is not substantially equal to an outside air temperature.

主权项

1. 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.