5. Operation
5.1
Precautions when starting the fan
Warning
Be sure to close the inspection door of the silencer box before
operating the fan.
(1) Close the damper and turn the unit ON and OFF once or twice to confirm that the unit is
operating normally without any unusual noise or vibrations. Moreover, check the rotation
direction of the fan at that time.
If the fan rotates in the reverse direction, swap two of the three wires of the power cable.
Warning
Be sure to turn off the main power before changing the wiring of the
fan.
(2) Turn on the power, and watch the unit closely until it reaches full speed.
At that time, carefully check for unusual noise, vibrations, current, or any other abnormal
condition.
(3) Start the continuous operation, and gradually open the damper.
In order to check the condition of each part, keep the fan running at a low flow rate (light
load) for 20 to 30 minutes.
At that time, ensure that the fan does not run at a rate where surging may occur.
(4) Gradually open the damper until the fan reaches the full load operation.
Keep it running under the condition for 1 to 3 hours, and check the temperature, vibrations
and noise at each section of the fan.
In addition, check that the motor current value is normal.
Note that the (electrical) current value becomes higher when the temperature of flowing air
is lower than the room temperature.
The bearing temperature may become slightly higher than usual for about one to two hours
after the start of operation. If there are no errors in the machine, however, the temperature
stabilizes afterwards.
5.2
Precautions during the operation
(1) Frequently starting and stopping the fan quickly damages it. Use the following values as a
guide for the frequency of starting the fan.
Motor output
Startup frequency
7.5kW or less
Up to 6 times an hour
11kW to 22kW
Up to 4 times an hour
Warning
In the event of a power failure, be sure to turn off the main power.
Otherwise, when the power is restored, the fan suddenly starts, and
it is dangerous.
5-1
