York Rooftop Unit ZH090E54B5B5BCA2A1

Warning: Follow NFPA 72 requirements for smoke detector maintenance

Upload a photo of the cleaned smoke detector

Enter any issues found during the maintenance

Sign off on the smoke detector maintenance

1. Remove the dot plugs from the duct panel (see Figures 12 and 13 for location)

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

The tubes must be inserted and held in a position perpendicular to the air flow so that velocity pressure will not affect the static pressure readings

3. Use an Inclined Manometer or Magnehelic to determine the pressure drop across a dry evaporator coil

Measuring the pressure drop across a wet coil under field conditions could be inaccurate

To assure a dry coil, the compressors should be de-activated while the test is being run

After installation has been completed

1. Check the electrical supply voltage being supplied

Be sure that it is the same as listed on the unit nameplate

2. Set the room thermostat to the off position

3. Turn unit electrical power on

4. Set the room thermostat fan switch to on

5. Check indoor blower rotation

The tension on the belt should be adjusted as shown in Figure 28 and Table 31

If the unit is equipped with power exhaust fans or a return air fan, check belt tension and adjust as necessary

PROCEDURE FOR ADJUSTING BELT TENSION

1. Loosen the four bolts holding the motor base to the channels

2. Adjust the belt by turning nuts "A" (see detail "B")

3. Using a belt tension checker, apply a perpendicular force to one belt at the midpoint of the span as shown

CAUTION: Only qualified personnel should make blower speed changes, strictly adhering to the fan laws.

Before making any blower speed changes review the installation for any installation errors, leaks or undesirable systems effects that can result in loss of airflow.

Even small changes in blower speed can result in substantial changes in static pressure and BHP.

BHP and AMP draw of the blower motor will increase by the cube of the blower speed.

Static pressure will increase by the square of the blower speed.

Calculate the new DD using the formula: Required CFM / Measured CFM × Existing DD = New DD