Grain Systems PNEG-163-08 - Manual (Page 27)

PNEG-163-08 Centrifugal Fan 27
6. User Servicing Instructions and Troubleshooting
Important Information Regarding Fuse Replacement
This product employs overload protection (fuse). A blown fuse indicates an overload or short circuit
situation. If the fuse blows, disconnect all power to the product. Replace the fuse as per the user servicing
instructions (follow product marking for proper fuse rating) and check the product. If the replacement fuse
blows, a short circuit may be present and the user should discontinue use of the product until customer
service can be contacted for further assistance.
Fan Wheel Removal and Installation
The fan wheel is secured to the motor shaft by the use of a taper-lock bushing, motor shaft key and cap
screws. The size, quantity and torque of cap screws required will depend on the model of the fan.
Removal
1. LOCK OUT THE MAIN POWER SUPPLY and remove the fan guard and inlet cone.
2. Remove the three (3) cap screws from the clearance holes in taper-lock bushing. Inspect for thread
damage and set aside for later reinstallation. (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 wheel. These cap screws should
not be used for reassembly, 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 wheel to prevent it from turning and GRADUALLY TURN IN THE CAP SCREWS (up to 1/4
turn at time), until the wheel breaks loose from the bushing and motor shaft. Carefully remove
bushing and wheel. (With the wheel free from the bushing, a wheel puller can be used to pull the
bushing off of motor shaft, if required.) Reattach bushing onto wheel to prevent the loss of parts and
also to maintain the original alignment of bushing to wheel. Inspect wheel and bushing at this time,
looking for any cracks, thread or bolt damage, warpage, etc. Consult the dealer or the factory for any
questions concerning damage.
DANGER
Always disconnect and lock out power before working on or around fan.
CAUTION
Although the taper-lock method of retaining the wheel onto the motor shaft is
very simple and obvious, it is essential that the following points be read
carefully and fully understood, as improper installation can result in serious or
fatal injury caused by a loose, fast flying wheel.
THREADED BUSHING HOLES: The threaded holes within the bushing are
provided for disassembly purposes only. Do not attempt to use these holes for
reassembly, as they will not allow the parts to become locked onto the shaft,
thereby causing an extremely hazardous operating condition.
CLEARANCE HOLES: When reassembling parts, the cap screws must be
installed through the UNTAPPED CLEARANCE HOLES to cause the wheel to
be pulled forward onto the tapered bushing, thus locking the parts securely
onto the motor shaft. Refer to
Step 4 on Page 28 (under Installation section)
for assembly details.