The unit airflow is set by making adjustments in the motor sheave during test and balance stage of start-up.

Follow the steps below for making these adjustments.

Belt Removal

1. First loosen the four mounting plate nuts on the topside of the plate to allow the motor mount to slide freely.

2. Now loosen the back-up lock nuts on the adjustment bolts for the mounting plate.

3. Loosen mounting plate adjustment bolts enough the belt can be removed off the motors adjustable sheave. Remove belt and set aside.

Key Removal

4. Now loosen the Allen head set screws on the adjustable sheave pulley to allow the Key in the keyway to be removed. Remove the Key and set it aside for now.     

Motor Sheave Adjustment

5. Turn the outside adjustable sheave clockwise until it stops. Ensure that the Adjustable sheave Keyway lines up squarely with the other half of the motor sheave. If the keyway stops a little before or after proper alignment with the motor sheave keyway just rotate enough forward or backwards so they both line up correctly. 

You are now ready to make adjustment based on the information provided in the IOM provided with the unit for airflow.

 Fan Curve information is also located below Warning on this page for Medium Foundation DOE and A2L products. 

Once the turns have been set, install the Key back into the Keyway and tighten set screws with the Allen wrench. this will complete the airflow adjustment.

Now that the airflow has been set, reverse the steps above to place the unit into operation to verify correct airflow adjustment has been made. Repeat steps again if airflow is still incorrect and requires further airflow adjustments.

Installing the Belt

6. Now that the Key is re-installed following the fan CFM adjustment place the belt back into the groove. Using the motor mount alignment bolts to tighten motor mount plate until correct belt tension is achieved. 

See information "How to adjust blower belt tension" below Warning for proper adjustment. 

7. Once belt is adjusted secure alignment bolts by tightening down the two-alignment bolt back up nuts. 

8. Now tighten down the four motor mount plate bolts. 

This will complete the belt installation. Verify everything loosen and removed prior is tighten again and installed correctly. 

Once again it is recommended to verify the belt tension is correct and did not get over tightened during final motor mount tightening. 

WARNING:

Information in this article is intended for use by individuals possessing adequate backgrounds of electrical and mechanical experience and who comply with all federal, state, and local laws, rules, orders, or regulations related to the installation, service, or repair of a heating or central air conditioning product. Any attempt to install, service, or repair a heating or central air conditioning product may result in personal injury and/or property damage. The manufacturer or seller cannot be responsible for the interpretation of the information contained herein, nor can it assume any liability in connection with its use.