COOK PLC - Manual (Page 2)

2
Wheel-to-Inlet Clearance
The correct wheel-to-inlet clearance is critical to proper
fan performance. This clearance should be verified before
initial start-up since rough handling during shipment could
cause a shift in fan components. Refer to wheel/inlet draw-
ing for correct overlap.
Adjust the overlap by loosening the wheel hub and mov-
ing the wheel along the shaft to obtain the correct value.
A uniform radial gap (space between the edge of the
cone and the edge of the inlet) is obtained by loosening the
inlet cone bolts and repositioning the inlet cone.
Wheel/Inlet Overlap
Size Overlap
120
.250
135
150
.313
165
.375
180
195
.438
210
225
.500
245 .563
270 .625
300 .688
330 .625
365 .688
402 .750
445 .875
490 .938
540 1.063
600 1.108
660 1.313
730 1.438
See Detail A
Overlap
Radial Gap
Detail A
Scale 2.000
Isolators
Floor Mounted Spring Isolators
• Mount fan and motor on an isolation base (if supplied).
• Elevate fan (or isolation base) to operating height and
insert blocks to hold in position.
• Position isolators under the fan and/or isolation base
and vertically align by inserting leveling bolt through
mounting holes in the fan or the base. The isolator
must be installed on a level surface.
• Adjust the isolators by turning the leveling nut counter
clockwise several turns at a time alternately on each
isolator until the fan weight is transferred onto the isola-
tors and the fan raises uniformly off the blocks. Then
remove the blocks.
• Turn lock nut onto leveling bolt and secure firmly in
place against the top of the mounting flange or frame.
• Secure isolators to mounting surface.
Floor Mounted Rubber-In-Shear (RIS) Isolators
• Mount fan and motor on an isolation base (if supplied).
• Elevate fan to provide room to insert isolators between
base and foundation or between the fan and foundation
and block in position.
• Position isolators under isolation base or fan and
secure bolts.
• Remove blocks and allow unit to rest on floor. Isolators
must be installed on a level surface (leveling should not
be required).
• Secure isolators to mounting surface.
Duct Installation
Efficient fan performance relies on proper installation.
If the fan has an open inlet (no duct work), be sure it is
placed one fan wheel diameter away from walls and bulk-
heads. Refer to figure 2.
Refer to the PLC catalog for discharge wall proximity
factors.
Note
Although a certain amount of vibration is inherent in
operating centrifugal fans, extreme vibration is a seri-
ous problem that may cause structural and mechani-
cal failure.
Rubber-In-Shear Isolator Spring Isolator
Figure 1 - Floor Mount Isolators
Minimum
1 wheel
diameter
Figure 2 - Non-ducted Inlet Clearance
Wiring Installation
All wiring should be in accordance with local ordi-
nances and the National Electrical Code, NFPA 70.
Ensure the power supply (voltage, frequency, and cur-
rent carrying capacity of wires) is in accordance with
the motor nameplate.
Lock off all power sources before unit is wired to
power source.
Leave enough slack in the wiring to allow for motor
movement when adjusting belt tension. Some frac-
tional motors have to be removed in order to make the
connection with the terminal box at the end of the
motor. To remove motor, remove bolts securing motor
base to power assembly. Do not remove motor mount-
ing bolts.
Personal Safety
Disconnect switches are recommended. Place
the disconnect switch near the fan in order that
the power can be swiftly cut off in case of an
emergency, and in order that maintenance
personnel are provided complete control of the
power source.