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CAUTION!
The bearing life is estimated by calculations according to ISO 281:2007-02 to give a L10 life. Beyond each
periodical maintenance, our recommended bearing condition check frequency is at each lubrication. Depending
on the results, bearings may need to be replaced.
CAUTION!
Lubrication intervals are based on a bearing operating temperature of +167°F (frames 63 to 200) and +185°F
(frames 225 to 500). Some designs may vary. An increase of the ambient temperature will raise the bearing
temperature correspondingly. For each 59°F of temperature rise, the relubrication period must be reduced by
half (i.e. must be more frequent).
ATTENTION!
Where motors are mounted inside fan housings, and where grease re-lubrication points have been mounted on
the exterior of the fan housing, there will be an additional nameplate affixed to the product which will state the
grease type, quantity and re-lubrication interval.
MOTORS WITHOUT LUBRICATORS
Where motors are not fitted with bearings that can be re-lubricated (WEG 48-210T NEMA frames), then the following steps
must be taken:
Motors operating in ambient temperatures up to +122°F;
After 20,000 hours running, or 3 years, whichever is the shorter, (10,000 hours where motor speed exceeds 1800 rpm),
the motor should be dismantled, shaft seals and bearings replaced and the bearings re-lubricated.
To re-lubricate motors which are mounted in an airstream with a temperature above 392°F or above (where the motor is
designed for used within a Smoke Extraction fan), the special grease used has a very low fill requirement. These fans, therefore,
do not have re-lubrication facilities. Any old grease must be washed out with a designated solvent. The bearings must be
refilled with grease leaving the housing empty. If a bearing is removed from the rotor, it must be discarded and a new one
fitted, using the approved grease.
10. TESTING (FANS AND CONTROLS)
It is recommended that fire safety systems are tested every 6 months. However, ideally, these tests should be more frequent
(once per month or once every 3 months). This test must review all elements of the system [fans, controls, dampers etc.] to
confirm correct operation.
Note: Fans must only be run for short periods as no thermal overloads are in circuit for emergency condition.
11. LONG TERM RELIABILITY
Maintenance Engineers should consider performing a major refit after fans have been operating for 50,000 hours or if they
have been installed for a period of 10 years. If the condition of the motor winding has been seen to deteriorate during regular
maintenance (as detailed within section 8), then the motor must be replaced. Motors used within Fire Safety fans must NOT
be re-wound. It could potentially be extremely dangerous to refurbish such as motor using a standard motor rewind facility,
as these motors are specially developed for the smoke control application. The new motor must be manufactured in
accordance with current requirements as stated within the EN12101-3 specification.
Guidance on operating times before a re-fit is required can be obtained from Woods Air Movement USA on receipt of
full operational information, duty cycle, "HT" category, and other nameplate data. To maintain the fan's High Temperature
capability, motor replacement must be conducted by Woods Air Movement USA or our nominated service representatives.
8
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