Pressure Blower Instructions
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1. Follow steps 1 and 2 under Wheel Removal.

2. Unbolt housing from c-face of motor or motor mounting bracket if motor does not

have a c-face and rotate the housing to the desired discharge position.

3. To re-assemble, follow steps 4 through 7 under Assembly Instructions.


1. Follow steps 1 and 2 under Wheel Removal.

2. Unbolt housing from c-face of motor or motor mounting bracket if motor does not

have a c-face.

3. Remove bolts and cut caulk to split apart the inlet cover plate from the inlet side of

the housing and the drive cover plate from the drive side of the housing. Switch

cover plates between the two housing halves. Be sure to re-caulk between the

mating surfaces.

4. To re-assemble, follow steps 4 through 7 under Assembly instructions.


1. Good results

require a proper foundation.

Foundations should be level, rigid,

and of sufficient mass for the equipment. Concrete is preferable. Its mass should

be at least four times the fan weight. Adequately brace steel platforms in all

directions. The minimum natural frequency of any part must be at least 50%

higher than the fan running speed.

2. Shim the fan support points before tightening foundation bolts. Do not distort or

twist the equipment. Duct connections should be smooth and straight. Elbows

and other transitions should be located at least five wheel diameters from fan

inlet and outlet (see AMCA Publication 201 for further details).

Flexible con-


to used at inlet and discharge connections. The

fan should never

support or restrain

any duct weight or force.

3. Make sure the power is locked “OFF”.

4. Check wheel-to-inlet clearance to make sure it has not shifted during shipment

or handling. There should be approximately equal clearance between the hous-

ing sides and the wheel. Rotate wheel by hand to check that it runs free.

5. If the wheel is striking, correct it by loosening the hub set screws and reposition

the wheel on the shaft. Torque all set screws and turn by hand again.

6. Check the motor wiring and fusing in accordance with the National Electrical

Code and local requirements. Follow wiring diagram on the motor nameplates.

7. Chicago Blower requires that all appurtenances, including ductwork or stacks,

which are attached to the fan inlet or outlet, be independently supported, unless

prior approval has been obtained from Chicago Blower. Excess dead loads or

wind loads can distort the fan housing causing misalignment and possible

failure. Flexible connections are also necessary to prevent duct expansion or

movement from adding loads to the fan.


1. Lubricate fan bearings per instructions in packet attached to the fan. Use a premi-

um quality NLG #2 grade multi-purpose grease, such as Shell Alvania Grease 2.

Lubricate bearings immediately on receipt. Add enough grease to cause slight

purge at seals. It is common for bearings to purge excessive grease during first 24

to 48 hours of operation. See bearing manufacturer’s instructions enclosed for

lubrication schedule.

2. Bearing must be properly locked to the shaft. Check before operation. Make

sure bearing locking collar is in position and set screws are tightened to the

bearing manufacturer’s recommended torque levels. See bearing manufactur-

er’s instructions enclosed for details. The bearing set screws should be re-

torqued after eight and twenty-four hours of operation.


If the fan is to operate with its shaft vertical, reset the fan bearings as


a. With the shaft vertical, unlock the drive end bearing set screws and turn the

shaft by hand. This allows the wheel end bearing to take the gravity load of

the shaft and wheel.

b. Re-lock the drive end bearing locking device and replace and torque set

screws as required by the bearing manufacturer’s instructions so that this

bearing now takes only the belt pull.

3. Do not use “hi temp” greases. Many are not formulated for the high speeds

associated with fan bearings.


1. Alignment of the drives must be checked with a straightedge or string. Belt

tension must be properly adjusted to assure good belt and bearing life. Sheave

faces should be parallel and aligned within 1/16".

Use balanced sheaves.

2. With all belts in their proper grooves, adjust the centers to take up all slack.

Do not tighten belts too tight.

Normal belt tension can be determined by being

able to depress belt, at mid-point a distance equal to one belt width, with normal

finger pressure. It is normal on V-belt drives handling more than 20 HP to

“squeal” on startup.


After installing the fan per these instructions and the instructions of the manufac-

turers, make final safety checks to prevent injury to personnel or damage to the


Always block rotating parts to prevent windmilling while inspect-

ing the fan.

1. Lock power source in “OFF” position.

2. Check bearings for alignment and proper lubrication, with wheel and inside of

the housing clean and free of debris.

3. Check wheel position for proper clearance and rotation. Unblock rotating parts

and turn wheel by hand to insure that it rotates freely.

4. Check sheave set screws or bushings and wheel set screws for tightness. Check

foundation bolts and secure safety guards.

5. Start fan and allow unit to reach full speed, then shut down. During this short

period, check for rotation, excessive vibration, any unusual noise, or overheat-

ing of the motor. Check the motor amps drawn against the nameplate rating.

A plate over the fan inlet will limit the horsepower drawn during a test run with

limited ductwork.

6. After the trial run lock the power “OFF”.

7. Recheck for tightness of hold-down bolts, wheel set screws and keys, and

retighten if necessary. Recheck after eight and twenty-four hours of operation.

8. The run-in period should be at least eight hours. Check bearings a minimum of

once each hour during this period. Overgreasing may cause bearings to heat

up. There need be no concern if the bare hand can be held on the bearings

briefly. Bearings will vent extra grease and cool down after start-up. Recheck

torque of all bearing set screws after eight and twenty-four hours of operation

to insure levels are maintained per the bearing manufacturer’s recommended


10. Take vibration readings at the bearings, or the motor bearings if the fan wheel is

mounted directly on the motor shaft. Adhere to these limits. Velocity Limits in inch-

es/second – Normal: .15; Alarm: .22; Shutdown: .5.


To insure long life and trouble-free service, frequently check all bearing lubrication.

See the bearing manufacturer’s instructions packed with the fan. Should excessive

vibration develop, check the following possibilities:

1. Build-up of dirt or foreign material on the wheel.

2. Loose bolts on bearings, housings, foundation and drive.

3. V-belt drives improperly aligned. Belts must have proper tension, sheaves must

be balanced.

4. Check wheel set screws.

5. Foreign matter may have entered fan causing damage to wheel, shaft or bear-


6. Vibration may be coming from a source other than the fan. Stop the fan and deter-

mine if the vibration still exists. Disconnect the driver from the fan and operate it

by itself to determine if it produces vibration.

7. Proper clearance between the wheel and the inlet.

A preventive maintenance schedule is a necessity for extending fan life. Establish

a lubrication schedule based on time periods suggested in lubrication instructions

and by motor and bearing manufacturers.

After approximately one (1) month of operation, all base, hub, bearing, pedestal,

etc. bolts should be checked.

Potentially damaging conditions are often signaled in advance by change in vibra-

tion and sound. A simple, regular audio-visual inspection of fan operation leads to

correction of the condition before expensive damage occurs. Vibration levels

should be checked by an approved technician using electronic balancing equip-


If the fan is to remain idle for an extended period, fill bearing with grease. Protect

motor and exposed surfaces. Follow the motor manufacturer’s recommendations

for storage and rotate the shaft by hand several revolutions each month.

Mechanical Integrity:

Certain operating conditions reduce the built-in strength of

the fan impeller and may cause unsafe operation. It is the user’s responsibility to

inspect for these conditions as frequently as necessary and to make corrections as

required. Failure to comply with the following limits voids the Chicago Blower

Corporation warranty.

Maximum Safe Speed and Temperature:

Operation exceeding maximum safe

RPM and temperature even for a short time causes overstressing or fatigue crack-

ing of the impeller resulting in unsafe condition. Maximum safe speed and maxi-

mum safe temperature are shown on fan assembly drawings, catalogs or order



The warranty on Chicago Blower fans is our standard warranty. The

warranty on the motor is that extended by the motor manufacturer.