Blower Start Up
For proper unit function and safety, follow everything in this startup procedure in the order presented. This to be
done after the electrical and gas connections are complete.
• Voltage meter
Special Tools Required
• Tachometer
• Amperage meter
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. 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 static. See Trouble Shooting section in this guide.
4. Measure Motor Voltage, Amperage and Fan RPM
All access doors must be installed except the control center door and gas control door. 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 Trouble
Shooting section in this guide.
5. Settings for Optional Components
Optional Freeze Protection:
This shuts down the blower if the output temperature is below the set point. A timer allows the blower to
operate during startup. This will reset when turned off.
Typical settings are: Discharge temperature = 45°F
Timer = 5 minutes
Optional 2 Hour Time Delay:
This allows the unit to operate for up to 2 hours (1 to 120 min) after the control panel switch has been turned
off. The timer has an adjustment knob on it.
Optional Inlet Air Sensor:
This shuts down the heater if the incoming air temperature is higher than the set point. This switch will
automatically reset as temperature decreases. A typical setting is 60°F.
Blower
Housing
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Supply Blower
