Amcot ST Series - Page 32

AMCOT ST SERIES FIBERGLASS COOLING TOWER
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GENERAL MAINTENANCE
Mechanical System – Fan Assembly
After the blades are in position and secured, this position represents the starting point
for fan adjustment. This may or may not be the final position for operation!!
From here, you will need to use an Angle Meter and place on the blade to check blade angle. We
recommend using the midpoint along the length of the blade to check this angle. Do this to all of the
blades on your assembly. Make sure that the blades are within 1 degree of one another. In doing this,
some blades may no longer be at the starting pitch location. That is ok. It is more important that blade
angles are matching versus the indicators on the hub/fan assembly at this point. Failure to make sure
the blade angles are matching will result in excessive vibration and mechanical failure.
Once this is completed, you will want to test the amp draw on the motor by using a digital clamp meter,
or similar test tool. The amp draw reading should be at or below the amperage shown on the motor
nameplate for the voltage being used.
Fan Adjustment
If the amp draw is too high (above the nameplate amperage), this means you need to decrease the
pitch/angle of the fan blades. If the amp draw is too low (more than 10% below the nameplate
amperage), then you need to increase the pitch/angle of the fan blades to increase air flow.
Repeat this process until the amperage is within the proper range and all blades are within 1 degree
angle of one another.
Once the tower is in operation, slight motor and fan vibration is normal. However, if you see significant
vibrations occurring after following the above steps, this could mean that there is physical damage to
the fan assembly. Shutdown the motor, lockout the disconnect switch and visually inspect the fan
assembly for damage. If you locate damage, please contact your distributor, representative, or Amcot
immediately. It is not recommended that you operate the tower with a damaged fan installed.
If no damage is seen, check the mechanical support assembly for damage and verify all fasteners are
tight and secure. If nothing is apparent when doing visual inspection and you have reconfirmed that
blade angles are all correct, please contract Amcot immediately.
WARNING: Do not attempt to run your tower with excessive vibrations as this can cause major
mechanical or structural failures to the tower and could even pose a risk to your personnel.
FANS SHOULD BE INSTALLED SO YOU SEE THE ROTATION ARROWS ON THE BLADES WHEN
LOOKING DOWN THROUGH FAN GUARD.