Grain Systems PNEG-010 - Manual (Page 21)

6. Fan Operation
PNEG-010 Vane Axial Fan 21
Removal
1. LOCK OUT THE MAIN POWER SUPPLY and remove the fan guard and venturi.
2. Remove the three (3) cap screws from the clearance holes in taper-lock bushing. Inspect for thread
damage and set aside for later re-installation (do not use these bolts for Step 3 , bushing removal).
3. Install two (2) grade 5 (or better) cap screws into the THREADED HOLES in the bushing and turn
them in by hand until they bottom against the front surface of the blade. These cap screws should
not be used for re-assembly, as some thread distortion could occur during the removal operation.
Grade 5 screws are marked with three (3) 120° spokes on the head and are more durable than low
strength unmarked bolts.
NOTE: Do not attempt to use low strength (unmarked) bolts to remove the bushing, as the bolts may
break off.
4. Block blade to prevent it from turning and GRADUALLY TURN IN THE CAP SCREWS (up to
1/4 turn at time), until the blade breaks loose from the bushing and motor shaft. Carefully remove
bushing and blade. (With the blade free from the bushing, a blade puller can be used to pull the
bushing off of motor shaft, if required). Re-attach bushing onto blade to prevent the loss of parts and
also to maintain the original alignment of bushing to blade.
Inspect blade and bushing at this time, looking for any cracks, thread or bolt damage, warpage, etc.
Consult your dealer or the factory for any questions concerning damage.
Installation
1. Carefully clean motor shaft, key, bushing and bore of blade. MAKE SURE MAIN POWER IS
LOCKED OUT and that shaft and key are completely free of rust and burrs. DO NOT lubricate the
bushing or cap screws. CHECK AND MAKE SURE ALL MOTOR MOUNT BOLTS ARE PROPERLY
TIGHTENED. Before installing the blade, check the following:
a. All foreign material should be removed from the blade.
b. Carefully inspect the blade weldment and hub casting for damage, cracks or other defects.
Contact the factory if there is any question regarding the structural integrity of the blade.
2. Slide blade over motor shaft and locate it as far onto the motor shaft as possible.
3. Align the keyway in the bushing with the key and SLIDE bushing onto motor shaft. Do not attempt to
drive the bushing onto the shaft, as it may damage the motor bearings.
4. Rotate the bushing and blade so their key slots are in line and loosely attach the blade to the bushing.
MAKE SURE THE CAP SCREWS ARE INSERTED INTO THE UNTHREADED CLEARANCE
HOLES IN THE BUSHING. Refer to previous CAUTION note
on Page 20 . Locate the bushing so it
is approximately flush with the end of motor shaft. Make certain that the proper cap screws are used
for re-assembly and no damage has occurred to these screws during disassembly. Use only the
special type bolts supplied with the original blade.
5. Use an INCH-POUNDS torque wrench and GRADUALLY TIGHTEN the three (3) cap screws
(1/4 turn at a time) until the taper bushing becomes fully seated. Refer to the following chart
on Page 22 for recommended cap screw tightening torques. DO NOT EXCESSIVELY
OVERTIGHTEN THE BUSHING.
6. Turn blade by hand and check it for freedom of rotation and uniform clearance around venturi before
re-installing the fan guard.