FloAire USI-FA - Manual (Page 4)

SET SCREW TIGHTENING SCHEDULE
1. Before initial operation of the fan, tighten set screws
according to the procedure outlined below.
2. After 500 operating hours or three months, whichever
comes first, tighten set screws to the full
recommended torque.
3. At least once a year, tighten set screws to the full
recommended torque.
PROCEDURE FOR TIGHTENING SET SCREWS IN
BEARINGS AND HUBS
One Set Screw Application
Using a torque wrench, tighten the set screw to the
torque recommended in Table 1.
Two Set Screw Application
1. Using a torque wrench, tighten one set screw to half
of the torque recommended in Table 1.
2. Tighten the second set screw to the full recommended
torque.
3. Tighten the first set screw to the full recommended
torque.
VARIABLE FREQUENCY
DRIVES AND MOTORS
There are occasions when a Variable Frequency
Drive (VFD) will cause poor motor performance and
possible damage. To avoid these problems, the
Company recommends the following:
1. Select compatible motor and VFD converter; if
possible, the motor and the converter should be
from the same manufacturer or at least the
converter selected should be recommended by the
motor manufacturer.
2. A motor shaft grounding system should be used to
prevent motor bearing damage from eddy currents.
NOTE: The Company will not honor motor
warranty claims if the customer fails to follow
these recommendations.
Page 4
Table 1. Recommended Tightening Torque
for Set Screws
Set Screw Diameter Torque (in-lbs)
#10 35
1/4 80
5/16 126
3/8 240
7/16 384
1/2 744
9/16 1080
5/8 1500
3/4 2580
7/8 3600
1 5400