7
Airflow System Start-Up
For proper unit function and safety, follow everything in this start-up procedure in the order presented. This is to
be done after the electrical connections are complete.
1. Check Voltage
Before starting the unit compare the supplied
voltage with the units nameplate voltage and the
motor voltage.
2. Check Blower Rotation
If the blower is rotating in the wrong direction, the
unit will move some air but not perform properly. To
check the rotation, open the blower access door
and run the blower momentarily to determine the
rotation.
To reverse the rotation, turn the power off and use
the following procedure:
• For single phase units, rewire the motor per the
instructions on the motor.
• For three phase units, interchange any two
power leads. This can be done at the motor
starter.
3. Check for Vibration
Check for unusual noise, vibration or overheating
of bearings. Excessive vibration maybe
experienced during initial start-up. Left
unchecked, excessive vibration can cause a
multitude of problems, including structural and/or
component failure. Many conditions can be
discovered by careful observation. If the problem
is wheel unbalance, in-place balancing can be
done providing there is access to the fan wheel.
Generally, fan vibration and noise is transmitted to
other parts of the building by the ductwork. To
eliminate this undesirable effect, Greenheck has
used a heavy canvas connection between the
scroll and the discharge of the fan. If noise is an
issue, we recommend using heavy canvas
connections on the inlet of the fan. Refer to the
“Troubleshooting” section of this manual if a
problem develops.
4. Air Volume Check and Measurement
Along with the building balance, the units air
volume (cfm) should be measured and compared
with its rated air volume. This unit is flexible for
varying air volume, but the actual air volume
should be known for making final adjustments. The
most accurate way to measure the air volume is by
using the pitot traverse method in the ductwork
away from the blower. Other methods can be used
but should be proven and accurate. To adjust the
air volume, change the fan rpm or the system
losses.
See Troubleshooting section in this guide.
5. Measure Motor Voltage, Amperage and
Fan rpm
All access doors must be installed. Measure and
record the input voltage and motor amperage(s).
To measure the fan rpm, the blower door will need
to be removed. Minimize measurement time
because the motor may over amp with the door
removed.
Compare measured amps to the motor nameplate
full load amps and correct if over amping. See the
Troubleshooting section in this guide.
Pre-Start Check List
1. Disconnect and lock-out all power switches to
fan.
2. Check all fasteners, set screws and locking
collars on the fan, bearings, drive, motor base
and accessories for tightness.
3. Rotate the fan wheel by hand and assure no
parts are rubbing.
4. Check the V-belt drive for proper alignment and
tension.
Special Tools Required
• Voltage meter
• Tachometer
• Amperage meter
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