York Rooftop Unit ZH150E54D5B5BCA2A1

Check the electrical supply voltage being supplied

Set the room thermostat to the off position

Set the room thermostat fan switch to on

Check blower drive belt tension

Check the unit supply air (CFM)

Measure evaporator fan motor's amp draw

Check if the unit is equipped with additional fans

Belt Tension Adjustment Procedure

Loosen the four bolts holding the motor base to the channels

Adjust the belt by turning nuts 'A'

Apply perpendicular force to the belt using a belt tension checker

Enter the deflection distance obtained

Use the recommended deflection force per the Belt Adjustment Table

Was the belt tension checked at least two times during the first 24 hours of operation?

Review installation for errors, leaks, or undesirable system effects

Ensure only qualified personnel make blower speed changes

Blower Speed Change Considerations

Verify understanding of fan laws

Are you aware that BHP and AMP draw increase by the cube of the blower speed?

Are you aware that static pressure increases by the square of the blower speed?

Is the smoke detector securely mounted?

Check for any visible damage to the smoke detector

Turn off the power to the smoke detector

Remove the smoke detector cover

Clean the smoke detector using a vacuum or soft brush

Reattach the smoke detector cover

Turn the power back on to the smoke detector

Remove the dot plugs from the duct panel

Insert eight inches of 1/4 inch metal tubing into the airflow on both sides of the indoor coil

Ensure tubes are perpendicular to the airflow

Determine the pressure drop across a dry evaporator coil using an Inclined Manometer or Magnehelic

Are the compressors de-energized before taking measurements?

Determine the CFM through the unit from the pressure drop indicated by the manometer

Adjust Measured CFM to Required CFM using SUPPLY AIR DRIVE ADJUSTMENT