AAON LN-140 - Manual (Page 27)

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5. Determine whether the pin is in the HUB
or RET
Figure 11 - Fan HUB and RET Castings
6. Determine the current blade pitch and the pin location for the new blades
Table 3 - Return/Exhaust Fan Pin Location
Type
Bushing
Mount
Blade Pitch Angle
20° 25° 28° 30° 33° 35° 38° 40° 45° 50°
5Z
A - RET - RET RET RET HUB HUB HUB HUB
B - HUB - HUB HUB HUB RET RET RET RET
Table 4 - Return/Exhaust Fan Pin Location
Type Rot.
Blade Pitch Angle
20° 25° 28° 30° 33° 35° 38° 40° 45° 50°
5Z
R - 4 - 3 2 1 4 3 2 1
L - 1 - 2 3 4 1 2 3 4
7. Replace fan blades in the new pin
location and reassemble the fan
Replace the blades with the pin in the 1, 2,
3, or 4 groove position of either the HUB or
RET. Assemble the fan making sure to place
the blades in their previous blade sockets, to
match up the previous orientation of HUB
and RET and to replace any balancing
weights in their previous locations. Tighten
bolts in a cross pattern to 5-6 ft-lbs. of
torque.