118
Maintenance
JOHNSON CONTROLS
5276178-JIM-C-0118
OUTLET TUBES
FLUE BAFFLE
REMOVE
SCREWS
SECTION “A” - “A”
FIGURE 52- TYPICAL FLUE BAFFLE
The restrictor plate must also be sealed to furnace tube
sheet.
FIGURE 53 - EXAMPLE OF FC FAN SHAFT/
WHEEL MARKING
LD06355
LD06355
Forward Curved Fans
The forward curved fan wheel must be removed through
the fan discharge opening. The location of other clamps,
fan wheel, and shaft must be marked so each of these
components can be reassembled in the same location
-
see Figure 53.
This will preserve the balance of the
rotating assembly. Proceed with the following steps:
1. Disconnect all duct work or guards attached to the
blower housing to permit unobstructed access.
2. Remove the cut off plate attached at the discharge
or blast area of the blower housing.
3. Thoroughly clean the shaft of all grease and rust
inhibitor. Be careful not to contaminate the bearing
grease. Use emery cloth to remove all rust or the
wheel may become “locked” to the shaft.
4. Loosen and remove set screws on both bearing
locking collars. Inspect and, if necessary, re-
place.
5. Loosen and remove set screws from both sides of
the wheel hub. Inspect and, if necessary, replace.
6. Using a rubber mallet or brass bar, slowly drive
the shaft in one direction until the set screw marks
on the shaft are fully exposed. File the marks
completely smooth. Drive the shaft in the opposite
direction and file smooth the set screw marks. Con
-
tinue to clean the shaft of all dirt and residuals.
7. To remove the key, use a rubber mallet or brass bar
to drive the shaft and wheel in one direction. Drive
the key in the opposite direction using a nail set or
smaller size key stock until the key is completely
free of the wheel. Be sure that key does not get
bent by allowing it to ride up the key way edge.
The slightest bend will prevent quick assembly.
Should this occur, replace the key stock.
8. Remove the shaft, supporting the weight of the
wheel, particularly for larger diameter wheels. Do
not allow the weight of the shaft to be supported
by one bearing as you disassemble.
9. Remove the wheel through the discharge or outlet
area of the blower housing.
10. Reassemble in reverse order, centering the wheel
between the edges of the inlet venturi. If bearings
were removed or replaced, be sure to reuse any
shim stock found between the mounting support/
plate and bearing housings.
11. Torque all hardware.
Fan Shaft Bearings
When removing and replacing the bearings, care should
be taken to ensure that the area where the bearings fit
on the shaft does not become scored or damaged. The
shaft in this area should be thoroughly cleaned before
the bearing is removed and again before the new bearing
is installed.
LD14103
Summary of Contents for 40 25 TON
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