Troubleshooting:
Problem | Possible Cause | Corrective Action |
Airflow too high | • External static pressure may |
| be too low. |
•Check the evaporator coil pressure drop through the display interface. Pressure should match the recommended pressure drops indicated on the chart based on Module size. If the pressure drop is above the recommended settings, decrease the blower speed until the pressure drop matches the recommended setting. See “Calibrate airflow manually” on page 17.
Temperature control | • Cooling and reheat settings |
not precise enough | are not close enough. |
| • Reheat PID loop is not |
| properly tuned. |
| • SCR controller is not |
| working. |
| • The mode of operation is |
| turned off. |
| • |
| been activated by a user- |
| defined input with the |
| equipment. |
| • Return air temperature is |
| reading incorrectly. |
•Check setpoints for cooling and heating as well as deadbands.
•Tune the PID loop for accurate reheat operation.
•Confirm the operation of the SCR controller.
•Check to verify that the proper modes of operation, cooling, and reheat are activated. A Module must have specific options installed to allow all modes of operation to be active.
•Review event log to see if this alarm input has been activated.
•Return air is not coming from the common space and may be influenced by a close heat source or a discharge air duct affecting return air temperatures. Try to eliminate the hot or cold air stream or relocate the sensor for better room temperature readings.
Humidification | • Check the setpoints for |
control is not | humidification and |
precise enough | dehumidification. |
| • Humidifier may not be |
| operating correctly. |
| • The mode of operation is |
| turned off. |
| • |
| has been activated by |
| customer interface with |
| equipment. |
| • The room is not properly |
| sealed internally to maintain |
| vapor pressure in the |
| controlled space. |
•Verify that the setpoints are not too far apart. Typical setpoint between humidification and dehumidification is 10%.
•Verify humidification operation. Ensure that there are no humidifier alarms that could impede the humidification process.
•Ensure that the proper modes of operation, humidification and dehumidification, are activated. A Module must have specific options installed to allow all modes of operation to be active.
•Review the event log to see if this alarm input has been activated.
•The room must have an adequate vapor barrier installed to maintain humidification and dehumidification setpoints. The vapor barrier is inadequate if humidity in the controlled space changes based on influences from the surrounding air outside the controlled space.
68 | NetworkAIR IR Operation, Maintenance, and Troubleshooting |
