25
START-UP OPERATION
Before starting up or operating the unit, verify all fasteners are secure and tight. Check the set screw in the
wheel hub, bearings, and the fan sheaves (pulleys). With power and gas OFF to the unit or before
connecting the unit to power, turn the fan wheel by hand. Verify it is not striking the inlet or any
obstructions. If necessary, re-center.
Special Tools Required: Standard Hand Tools, AC Voltage Meter, Tachometer, Amperage Meter,
Manometer, Differential Pressure Gauge
Start-up Procedure
1. Check all electrical connections are secure and tight.
2. Check pulley alignment and belt tension. Refer to “Pulley Alignment/Proper Belt Tension” on
page 30.
3. Inspect the condition of the intake damper and damper linkage, if applicable.
4. Remove intake filters if not already installed, inspect the air stream for obstructions. Install intake
filters.
5. Compare the supplied motor voltage with the fan’s nameplate voltage. If this does not match, correct
the problem.
6. Place the external disconnect to the ON position to start the unit. Immediately place the disconnect
switch off. Check the rotation of the fan with the directional arrow on the blower scroll. Reversed
rotation will result in poor air performance, motor overloading and possible burnout. For units equipped
with a single-phase motor, check the motor wiring diagram to change rotation. For 3-phase motors,
any two power leads can be interchanged to reverse motor direction.
7. When the fan is started, observe the operation and check for any unusual noises.
8. Place the external disconnect switch back to the ON position. The system should be in full operation
with all ducts attached. Measure the system airflow. The motor sheave (pulley) is variable pitch and
allows for an increase or decrease of the fan RPM. If an adjustment is needed, refer to “Pulley
Adjustment” on page 29. Refer to “Pulley Combination Chart” on page 28 for adjustment
specifications.
9. Once the proper airflow is achieved, measure and record the fan speed with a reliable tachometer.
Caution - Excessive speed will result in motor overloading or bearing failure. Do not set fan
RPMs higher than specified in the maximum RPM chart. Refer to “Troubleshooting” on page 37
for more information.
10. Measure and record the voltage and amperage to the motor. Compare with the motor’s nameplate to
determine if the motor is operating under safe load conditions. Once the RPM of the ventilator has
been properly set, disconnect power. Re-check belt tension and pulley alignment, refer to “Pulley
Alignment/Proper Belt Tension” on page 30.
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