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9. LUBRICATION - HT FANS
CAUTION!
It is necessary to record the number of hours the motor has operated in order to determine when bearing
relubrication is required. If the motor is not running continuously, the date of installation must be recorded, since
relubrication is recommended every three to six months, even if the motor has not been run during this time.
WARNING!
Beware of all rotating parts!
Grease can cause skin and eye irritation when re-greasing. Follow all safety precautions specified by the grease
manufacturer.
SHIELDED/SEALED BEARINGS
Small motors (WEG NEMA 48-210T NEMA frames) which are fitted with 'sealed for life' ZZ/2Z bearings (that are pre- greased), must
be replaced after 20,000 running hours (if fans are continuously running). If the fan is a "dual mode" fan or if it is a dedicated fire
safety (smoke extract) fan, checks should take place every 6 months to determine if the fan (motor) bearings have become noisy
or appear to have become unbalanced. Check motor nameplate for determining the bearing type used.
MOTORS FITTED WITH GREASE RE-LUBRICATION POINTS
Bearing grease re-lubrication points are usually fitted to larger frame motors than those mentioned above. Regular maintenance
and adherence to re-greasing procedures will prolong bearing life. Failure to do this may shorten bearing life considerably.
Maintenance includes:
a) Attention to the overall bearing condition;
b) Cleaning and lubrication;
c) Detailed inspection of the bearings.
Although bearing problems may often be detected by listening for unusual bearing noise, more sophisticated equipment should
be used to obtain a quantified bearing condition analysis. Bearings must be lubricated to avoid metallic and direct contact of the
moving parts, and to provide protection against corrosion and wear. Lubricant properties deteriorate over time due to mechanical
operation, furthermore, all lubricants are subject to contamination under working conditions. For this reason, lubricants must be
renewed or replenished on a regular basis, in accordance with motor manufacturers recommendations.
NOTE!
Bearings with grease re-lubrication points must be replaced after 40,000 running hours or 5 years,
whichever occurs first.
LUBRICATION INTERVALS
I t should be noted that some grease types may cause higher bearing noise levels particularly at low temperatures,
or when intermittent operation does not allow the running temperature to exceed +68 °F.
Please contact Woods Air Movement USA if the normal fan and motor operating temperature is below +23 °F.
Grease type, lubrication intervals, grease quantity used, and the bearing type and its associated component clearances, are all
indicated on the motor nameplate. Lubrication intervals are dependent on motor size, running speed, working conditions, grease
type and the ambient operating temperature. If required, please contact Woods Air Movement USA for further advice related to
bearing lubrication or replacement.
NOTE!
If the supplied fan and motor assembly was intended and designed) for horizontal operation but is then
operated in a vertical position (i.e. with the motor shaft in the vertically up or vertically down position), then
bearing lubrication intervals must be reduced by half (i.e. must be more frequent).
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