55
Step 4: Remove the fan blades and replace
the pitch pins
Figure 38 - Pin Groove Location
Figure 39 - Pitch Pin Location
Figure 40 - Example Pitch Pin
Step 5: Replace the fan blades with the pitch
pin of the blade in the same groove and
reassemble the fan.
Replace the blades and assemble the fan
making sure to place the blades in their
previous blade sockets, to match up the
previous orientation of hub plate casings and
to replace any balancing weights in their
previous locations. Tighten bolts in a cross
pattern to 6.7 ft-lbs. of torque.
Step 6: Install the fan in the unit.
After placing the fan on the shaft, place the
key in the shaft, make sure the screw on the
bushing is aligned over the key and then
tighten the screw to 9 ft-lbs torque.
Adjusting Refrigerant Charge
Adjusting the charge of a system in the field
must be based on determination of liquid sub-
cooling and evaporator superheat. On a
system with an expansion valve liquid sub-
cooling is more representative of the charge
than evaporator superheat but both
measurements must be taken.
Before Charging
Unit being charged must be at or near full
load conditions before adjusting the charge.
Units equipped with hot gas reheat must be
charged with the hot gas reheat valves closed
while the unit is in cooling mode to get the
proper charge. After charging, operate the
The Clean Air Act of 1990 bans the
intentional venting of refrigerant
(CFC’s and HCFC’s) as of July 1,
1992. Approved methods of recovery,
recycling or reclaiming must be
followed. Fines and/or incarceration
may be levied for non-compliance.
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