A. Hardware:
All fan and hardware should be checked to make sure it is tight. Propeller set screws or taper-lock bushings should be
tightened to the torque values shown in
Tables 1 and 2
on page 4.
NOTE:
If any set screws have come loose, they must be thrown away and replaced.
NEVER
use set screws more
than once.
Replace with knurled, cup-point set screws with a nylon locking patch.
B. Motor Bearing Lubrication:
1. Motor Bearings:
Most smaller motors have sealed bearings that never require re-lubrication for the life of the motor. For any motors with
grease fittings, consult the motor manufacturers recommendations with reference to the lubrication frequency and the
type of grease that should be used.
DO NOT
over grease the motor bearings. Generally, 1-2 shots should be enough. Use a hand operated grease gun at
no more than 40 PSI.
DO NOT attempt to lubricate the motor bearings while the motor is running.
C. Prop Balance:
All propellers are balanced at the factory. It is not uncommon that additional “trim balancing” is required after the fan is
assembled. Trim balancing of the fan assembly, in the field, is typically always necessary for all replacement props.
Air stream material or chemicals can cause abrasion or corrosion of the fan parts. This wear is generally uneven and,
over time, will lead to the prop becoming unbalanced, causing excessive vibration. When that happens, the prop must
be rebalanced or replaced. The other air stream components should also be inspected for wear or structural damage
and cleaned or replaced if necessary.
After cleaning any fan propeller, it should be balanced.
There are two ways to balance a fan propeller:
1. Add balancing weights for fabricated aluminum, steel or stainless steel props:
Balance weights should be rigidly attached to the prop at a location that will not interfere with the fan hous-
ing nor disrupt air flow. They should (if at all possible) be welded to the prop. When trim balancing the prop,
on the fan,
be sure to ground the welder
directly
to the propeller. Otherwise, the welding current will likely
pass through the motor and damage the motor bearings.
2. Grinding off material for cast aluminum propellers:
If you are grinding on the prop to remove material, be very careful not to grind too much in one area. That
could affect the structural integrity of the prop.
D. Vibration:
As mentioned previously in this manual, excessive vibration can cause premature motor bearing failure that could lead
to catastrophic failure of the fan. After performing any routine maintenance, the vibration readings should be taken
again. New readings should be taken (maximum every 12 months) and compared to the previous readings.
If any
major differences are present, the cause should be determined and corrected before the fan is put back into
operation.
The most common causes of vibration problems are:
1. Propeller unbalance.
3. Poor fan inlet and/or discharge conditions.
2. Mechanical looseness.
4. Foundation stiffness.
E. Dampers and Shutters: (Airflow control devices)
Turn off and lock out power to the fan motor. Any dampers or shutters should be periodically inspected to make sure
all parts are still operable within their full range and there is no interference with any other fan components. Any bear-
ings or seals should be checked for their proper function. The manufacturers maintenance instructions should be fol-
lowed.
OMM-14-0509-page 8
BEFORE STARTING ANY INSPECTION OR MAINTENANCE, BE SURE FAN IS TURNED OFF, POWER IS LOCKED OUT
AND THE PROPELLER HAS BEEN CAREFULLY SECURED TO PREVENT WIND MILLING. IF THE OPERATING
CONDITIONS OF THE FAN ARE TO BE CHANGED (SPEED, PRESSURE, TEMPERATURE, ETC.) CONSULT
CINCINNATI FAN, OR OUR SALES OFFICE FOR YOUR TERRITORY, TO DETERMINE IF THE UNIT WILL
OPERATE SAFELY AT THE NEW CONDITIONS.
WARNING
V. ROUTINE INSPECTION & MAINTENANCE
Periodic inspection of all the fan parts is the key to good maintenance and trouble-free operation. The frequency of
inspections must be determined by the user and is dependent upon the severity of the application.
BUT,
it should
NEVER
exceed a 12 month period. The user should prepare an inspection and maintenance schedule and make sure
it is adhered to.
