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Recommended Relubrication
Frequency in Months
NOTE: If unusual environment conditions exist more
frequent lubrication is required (extreme
temperature, moisture or contaminants).
A good quality lithium base grease,
conforming to NLGI Grade 2 consistency,
such as those listed here may be used.
Table 2: Suggested Fan Bearing Greasing Intervals
Interval
(months)
Heavy duty in dirty, dusty locations; high ambient
1 to 3
temperatures; moisture laden atmosphere;
vibration.
12 to 24 hours per day, heavy duty, or if moisture
3 to 6
is present
8 to 16 hours per day in clean, relatively dry
6 to 12
atmosphere
Infrequent operation or light duty in clean
12 to 18
atmosphere
WARNING: Before taking any corrective action, make certain unit is not capable of operation during
repairs.
PROBLEM
Bad Bearings
Wheel unbalance
Belts too tight or too loose
Excessive Noise
Wheel improperly aligned and
or Vibration
rubbing
Loose drive or motor pulleys
Foreign objects in wheel or
housing
System resistance too high
Unit running backwards
Reduced airflow
Excessive dirt buildup on wheels
Improper wheel alignment
6
Models NYD & NYB • Tamper-Resistant Centrifugal Roof Exhaust Fans
Type of Service
Troubleshooting
CAUSE
Table 3: Grease Manufacturers
Manufacturer
U.S. Electric Motors
Chevron U.S.A. Inc
Mobil Oil Corporation
Texaco, Inc.
Amoco Oil Co.
Exxon
Shell
CORRECTIVE ACTION
Replace.
Clean and remove all dirt buildup off wheel. Check wheel
balance, rebalance in place if necessary.
Adjust tension, see figure 7.
Center wheel on inlet, see figure 2.
Align and tighten. See "Pre-Starting Checks", see page 3-4.
Remove objects, check for damage or unbalance.
Check system: Proper operation of backdraft or control
dampers, obstruction in ductwork, etc.
Correct as shown in figure 3.
Clean wheel.
Center wheel on inlets, see Pre-Starting checks and figure 2.
Grease (NLGI #2)
Grease No. 83343
Chevron SRI Grease #2
Mobilith
Mobil 532
Premium BRB #2
Texaco Multifak #2
Rykon Premium #2
Unirex N2
B Shell Alvania #2
®
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