OMM-11-0211-page 6
ASSEMBLY STEPS: (Below are general instructions. Obtain specific instructions from your drives dealer)
1. Remove belt guard and open shaft access holes. Remove the protective coating from the blower and motor shafts.
2. Loosen (don't remove) the four bolts in the side of the motor adjustment base. Now you can adjust the centerline
height of the base by turning the four bolts in the top of the adjustment base, next to the motor feet. Lower the motor
adjustment base so the motor shaft is as close to the fan shaft as possible. Now loosen (don't remove) the 4 bolts
holding the motor feet to the adjustment base.
NOTE:
The 4 nuts that secure the motor feet onto the motor slide base should be loosened
just enough
so the
motor will
slide
along the slide base
before
you loosen or tighten the belt tension adjustment bolt(s).
3. If you are replacing the belt(s) and/or sheaves, remove belt(s) from sheaves and then loosen the sheaves set screws
or taper-lock bushings to remove the sheaves.
4. Check the blower and motor shafts for any nicks or burrs. Remove any burrs with a file or emery paper.
5. Slide the new sheaves onto the blower and motor shafts.
DO NOT
drive or pound the sheaves on as this may dam-
age the blower and/or motor bearings.
6. Check the blower and motor shafts to make sure they are
parallel
and aligned as shown in
Fig. 2
on page 5.
7. Place the belt(s) over the sheaves.
DO NOT
force, pry or “roll” the belts, as this could damage the cords in the
belt(s). If there is more than 1 belt, all the belts should be a
“matched set”
.
8. Align the blower and motor sheaves with a straight-edge or string as shown in
Fig. 3
below. If the sheaves are not
the same width, align by sight. For more precise methods, consult your local drives dealer.
NOTE:
Any sheave with a taper-lock bushing will slide a little on the shaft as the bolts are tightened. You will need to
compensate for the sliding before performing
Step 9
.
9. Tighten the set screws in the sheaves or the bolts in the taper-lock bushings to the correct torque values as indicat-
ed in
Tables 2 and/or 3
on page 5.
10. Tighten the 4 bolts in the motor feet. Adjust the motor adjustment base until the belts become snug. Repeat
Steps 6
and
8
above.
11. Tighten the 4 bolts in the side of the adjustment base to secure it.
CAUTION: BEFORE ATTEMPTING STEPS 12 AND 15, MAKE SURE THE AREA AROUND THE BLOWER IS
SAFE AND SECURED SO NO ONE CAN GET NEAR THE BLOWER AND POSSIBLY GET INJURED
WHEN IT IS STARTED.
12. Unlock power to the motor and run the blower for 15-20 minutes to allow belts to “seat” properly.
Then turn off and
lock out power to the motor.
13. Loosen the 4 bolts in the side of the motor adjustment base and re-adjust the belt tension.
Final belt tension
should be checked with a “tensioning gauge”
. Repeat
Steps 6
and
8
above.
14. Tighten the 4 bolts in the side of the motor adjustment base.
15. Unlock power to the motor and run the blower for 8 hours. The belts should be running as shown in
Fig. 4
below. If
not, repeat steps 13 and 14 after
you have turned off and locked out power to the motor.
16.
Turn off and lock out power to the motor,
reinstall belt guard and cover the bearing/shaft access holes. Unlock the
power to the motor and run the blower.
17. After running the blower for 24 hours,
turn off and lock out power to the motor.
Then, remove belt guard. Repeat
Steps 13
through
16
above.
18. After running the blower for 100 hours,
lock out power to the motor
, remove belt guard and repeat steps 13
through 16. Repeat this periodically, but never more than a one year period.
Fig. 3
III. ELECTRICAL
A. Disconnect Switches:
All blower motors should have an independent disconnect switch located in close visual proximity to turn off the elec-
trical service to the blower motor.
Disconnects must be locked out in accordance with OSHA “lock out-tag out”
procedures any time inspection or maintenance is being performed on the blower and/or motor assembly.
The “lock out-tag out” procedure should be performed by a licensed electrician or authorized personnel.
All disconnects should be sized in accordance with the latest NEC codes (National Electric Codes) and any local
codes and should be installed only by a licensed electrician. “Slow blow” or “time delay” fuses or breakers should be
used since the initial start-up time for the blower motor, although rare, can be up to 10 seconds.
Straight edge
should touch
sheaves at
these 4 points.
Straight
Edge
Too Tight
Too Loose
Proper Tension
(Slight Bow)
Fig. 4
