Fan And Shaft Removal; Motor Location; Lubrication - Carrier AERO 39MN Installation, Start-Up And Service Instructions Manual

Fan and Shaft Removal —
wheel and shaft may be removed through inlet side of fan
housing. See Fig. 137. On plenum fans, remove side, top, or
end panel opposite inlet, wherever ductwork is not con-
nected. After removing panel, proceed as follows.
1. Remove drive belts as described in Fan Shaft Bearing
Removal section.
2. Block up fan wheel within housing to prevent dropping
when bearing bolts are removed.
3. Loosen bearing holddown bolts, block shaft up.
4. Loosen bearing setscrews and locking collar, and re-
move holddown bolts. On forward-curved fans, remove
cut-off plate. Remove fan wheel through discharge
opening.
NOTE: To facilitate easy removal of setscrew fastened
wheels, sheaves or bearings, remove the setscrew completely.
Taking care not to damage threads, insert a flat ended drift or
punch, tap lightly and carefully return the material displaced
on the shaft by the setscrew to its original place.
5. Remove bearing support channels and inlet ring from
one side.
6. Remove fan shaft and fan wheel from unit.
7. Remove fan shaft from fan wheel.
8. Replace shaft and wheel into fan in the reverse order of
their removal.
9. Inspect bearings and if serviceable, replace on shaft.
10. For airfoil and forward-curved fans, align fan wheel and
shaft assembly in fan scroll. Check cutoff location if
wheel failure damaged cutoff plate. For plenum fan,
align wheel and shaft assembly per manufacturer's di-
rections supplied with fan.
11. Tighten bearing holddown bolts, bearing setscrews, and
shaft setscrews.
12. Field balancing of shaft and wheel is recommended.
IMPORTANT: Replacement shafts must have a diam-
eter tolerance at bearing mount of +.0000 in./-.001 in.
nominal. Carrier specified parts are recommended.
The motor and motor base must be
Motor Location —
moved to place the motor at the front or rear of unit. The
proper location is the one that results in the longest drive cen-
terline distance. The motor may need to be replaced since the
conduit box may need to be reversed: The conduit box (if not
on top) should always be under the fan shaft for maximum
centerline distance and motor adjustment.
39-266d
Fig. 137 — Fan Shaft and Bearing Removal
On airfoil fans, the fan
INTERNALLY ISOLATED UNIT — When fan discharge is
altered the motor is moved, then all isolators must be read-
justed to assure proper unit isolation.
Rebalancing of the unit is recommended.

Lubrication

MOTORS — Lubricate in accordance with nameplate at-
tached to motor or with manufacturer's recommendations.
BEARINGS
Initial Fan Bearing Lubrication — Most bearings are greased
when they are manufactured and will not require additional
grease on start-up (verify specific manufacturer's recommenda-
tions). Some seepage of grease from the seals is normal during
the initial run-in period. For safety purposes, lock out and tag
equipment and wipe up any external grease from the bearings.
Monitor bearings after they have been run for several
minutes. Check bearings for excessive noise, vibration, and
temperature. Typical operating bearing temperature range
should be 100 to 150 F. The initial temperature may be higher
than the expected steady state temperature.
Bearing Lubrication Instructions — Lithium or lithium com-
plex base grease, conforming to NLGI (National Lubricating
Grease Institute) grade 2 consistency, and an oil viscosity of 455 to
1135 SUS (Saybolt Universal Seconds) at 100 F (100 to 250 cSt
[centistokes] at 40 C) may be used for relubrication.
Examples: Mobil Mobilith AW2
Mobil Mobilux #2
Shell Alvania #2
Texaco Multifak #2
Texaco Premium RB
Exxon Unirex N2
Amoco Amolith 2
Compatibility of grease is critical; consult with the grease
manufacturer and/or supplier for current grease specifications
to ensure compatibility.
To lube bearings, use a hand pump grease gun. Always
wipe the fitting and grease nozzle clean to avoid introducing
contamination into the bearing.
IMPORTANT: If possible, it is recommended to lubri-
cate the bearing while it is rotating, until grease purge
is seen from the seals. If this is not an option due to
safety reasons, follow the alternate lubrication proce-
dure below.
For safety, lock out and tag out the fan and restrain rotat-
ing components. Add one-half the recommended amount
shown in Table 35. Start the fan and run for a few minutes.
Stop the fan and lock out and tag out the unit. Add the second
half of the recommended amount. A temperature rise after lu-
brication, sometimes 30° F (17° C), is normal. Bearing
should operate at temperatures less than 200 F (94 C) and
should not exceed 250 F (121 C) for intermittent operation.
For relubrication guidelines, see Table 36.
NOTE: Tables 35 and 36 state general lubrication recommen-
dations based on experience and are intended as suggested or
starting points only. For best results, specific applications
should be monitored regularly and lubrication intervals and
amounts adjusted accordingly.
155