COOK AVA User Manual

VA/AVA/AF

WARNING

This unit has rotating parts. Safety precautions
should be exercised at all times during installation,
operation, and maintenance.
ALWAYS disconnect power prior to working on

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.

Vane Axial Inline Blowers

INSTALLATION, OPERATION, AND MAINTENANCE MANUAL

This publication contains the installation, opera­tion and maintenance instructions for standard units
of the VA/AVA/AF- Vane Axial Inline Blowers.

• VAD/VAB/VAHB • AVAD/AVAB

• AFB-C/AFBV-C • AFB-H/AFBV-H

• AFB-S/AFBV-S • AFD-C/AFDV-C

Carefully read this publication prior to any installa­tion or maintenance procedure.

Loren Cook catalog, VA/AVA/AF, provides additional
information describing the equipment, fan performance,
available accessories, and specification data.

For additional safety information, refer to AMCA publi­cation 410-96, Safety Practices for Users and Installers
of Industrial and Commercial Fans.

All of the publications listed above can be obtained
from Loren Cook Company by phoning [phone],
extension 166; by FAX at [phone]; or by e-mail at
[e-mail].

For information on special equipment, contact Loren
Cook Company Customer Service Department at (417)
869-6474.

Receiving and Inspection

Carefully inspect the fan and accessories for any dam­age and shortage immediately upon receipt of the fan.

• Turn the prop by hand to ensure it turns freely and
does not bind.

• Record on the Delivery Receipt any visible sign of
damage.

Outdoor Storage

To maintain good working condition of a Vane Axial when
it is stored outdoors, or on a construction site, follow the
additional steps below.

• Cover the inlet and outlet, and belt tunnel opening to
prevent the accumulation of dirt and moisture in the
housing.

• Periodically rotate the prop and operate dampers (if
supplied) to keep a coating of grease on all internal
bearing parts.

• Periodically inspect the unit to prevent damaging condi­tions.

Installation

To prevent damage to the fan during shipping, motors 25
HP and larger, and extremely heavy motors (cast iron or
severe duty) are shipped loose and must be field mounted
by bolting the motor on the motor mounting plate in the
existing mounting slots.

Handling

Handle your equipment with care. Some fans are pro­vided with lifting lugs or holes for easy handling. Others
must be handled using nylon straps or well-padded
chains and cables which protect the fan’s coating and
housing. Spreade r bars shou ld be used whe n lifting large
parts.

Axial fans should be lifted by using straps around the
fan housing only. DO NOT LIFT AXIAL FANS BY THE
MOTOR, MOTOR BASE, PROP OR FLANGES.

Storage

If the fan is stored for any length of time prior to instal­lation, completely fill the bearings with grease or mois­ture-inhibiting oil. Refer to Lubricants on page 6. Also,
store the fan in its original crate and protect it from dust,
debris and the weather.

VAD

Rubber-In-Shear Ceiling Isolators

Ceiling Mounted Spring Isolator

Figure 2 - Ceiling Mount Isolators

Non-ducted Inlet Clearance

MIN

1 DIA

Inlet Bell

Free Discharge

Correct

Incorrect

MIN

3 DIA

Inlet Duct Turns

Correct

Incorrect

Min 3

Dia

Isolation Installation

Note

Extreme vibration is a serious problem that may
cause structural and mechanical failure. To help
vibration and noise from being transferred to the
building, isolators are recommended.

Figure 1 -Floor Mount Isolators

Rubber-In-Shear Isolator

Spring Isolator

Floor Mounted Spring Isolators

a. Mount fan and motor on unitary base (if supplied).
b. Elevate fan (or isolation base) to operating height and

insert blocks to hold in position.

c. Position isolators under the fan 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.

d. 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 isolators and
the fan raises uniformly off the blocks. Then remove the
blocks.

e. Turn lock nut onto leveling bolt and secure firmly in place

against the top of the mounting flange or frame.

f. Secure isolators to mounting surface.

Duct Installation

Efficient fan performance relies on the proper installation
of inlet and discharge ducts. Be sure your fan conforms to
the guidelines below.

Non-Ducted Inlet Clearance

If your fan has an open inlet (no duct work), the fa n must
be placed one fan wheel diameter away from walls and
bulkheads.

Floor Mounted Rubber-In-Shear (RIS) Isolators

a. Mount fan and motor on a unitary isolation base (if sup-

plied).

b. Elevate fan to provide room to insert isolators between the

fan and foundation and block in position.
c. Position isolators under fan and secure bolts.
d. Remove blocks and allow fan to rest on floor. Isolators

must be installed on a level surface (leveling should not be

required).
e. Secure isolators to mounting surface.

Ceiling Mounted Spring and Rubber-in-Shear (RIS) Isola­tors

a. Elevate fan to operating height and brace.
b. Attach threaded rod to overhead support structure directly

above each mounting hole. Rod should extend to within a

few feet of fan.
c. Attach isolator to end of threaded rod using a nut on ea ch

side of isolator bracket.
d. Insert another section of threaded rod through the fan

mounting hole and isolator.
e. Attach two nuts to threaded rod in isolator.
f. Place adjusting nut and locking nut on threaded rod near

fan mounting bracket.
g. Alternately rotate adjusting nut at each mounting loc ation

until the fan weight is uniformly transferred to th e isolators.

Remove bracing.

Incorrect

Fan

Inlet Bell

Air Flow

Min

1 Dia.

Correct

Fan

Inlet Bell

Air Flow

Free Discharge

Avoid a free discharge into the plenum. This will result in

lost efficiency because it doesn’t allow for a static regain.

Correct

Incorrect

Inlet Duct Turns

For ducted inlets, allow at least 3 fan wheel diameters

between duct turns or elbows and the fan inlet.

2

Discharge Duct Turns

Discharge Duct Turns

Correct

Incorrect

MIN

3 DIA

Inlet Cone

1 foot

1/4 inch

Figure 3

When possible, allow 3 duct diameters between duct
turns or elbows and the fan outlet. Refer to the dra wings at
the top of page 3.

Correct Incorrect

Small

Duct

Diverging
Inlet
Cone

Air Flow

Fan

Large
Duct

Small

Duct

Inlet

Air Flow

Fan

Large
Duct

Belt and Pulley Installation

Belt tension is determined by the sound the belts make
when the fan is first started. Belts will produce a loud
squeal which dissipates after the fan is operating at full
capacity. If the belt tension is too tight or too loose, lost effi­ciency and possible damage can occur.

Do not change the pulley pitch diameter to change ten­sion. This will result in a different fan speed.

a. Loosen motor plate adjustment bolts and move motor

plate in order that the belts can easily slip into the
grooves on the pulleys. Never pry, roll, or force the
belts over the rim of the pulley.

b. Adjust the motor plate until proper tension is reached.

For proper tension, a deflection of approximately 1/4”
per foot of center distance should be obtained by

firmly pressing the belt. Refer to Figure 3.
c. Lock the motor plate adjustment nuts in place.
d. Ensure pulleys are properly aligned. Refer to Figure 4.

Tolerance

Center Distance

Up thru 12” 1/16”

12” up through 48 1/8”

Over 48” 1/4”

Maximum

Gap

Pulley Alignment

Pulley alignment is

OFFSET ANGULAR OFFSET/ANGULAR

A

W

CENTER

X

DISTANCE

Y

(CD)

adjusted by loosening
the motor pulley set­screw and by moving
the motor pulley on the motor shaft.

Z

B

GAP

GAP

Figure 4

Figure 4 indicates where to measure
the allowable gap for the drive alignment
tolerance. All contact points (indicated by
WXYZ) are to have a gap less than the
tolerance shown in the table. When the
pulleys are not the same width, the
allowable gap must be adjusted by half
of the difference in width (As shown in A
& B of Figure 4). Figure 5 illustrates
using a carpenter’s square to adjust the
position of the motor pulley until the belt

Figure 5

is parallel to the longer leg of the square.

Wiring Installation

All wiring should be in accordance with local ordinances
and the National Electrical Code, NFPA 70. Ensure the
power supply (voltage, frequency, and current carrying
capacity of wires) is in accordance with the motor name­plate.

Lock off all power sources befor e unit is wired to power
source.

Leave enough slack in the wiring to allow for motor move­ment when adjusting belt tension. Some fractional 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 mounting bolts.

Follow the wiring diagram in the disconnect switch
and the wiring diagram provided with the motor. Cor­rectly label the circuit on the main power box and
always identify a closed sw it ch to promote safety (i.e.,
red tape over a closed switch).

3

4

5

6

1
728

3
9

L

1

L2L

3

456
789

12

3

L

1

L2L

3

Low Voltage

208/230 Volts

High Voltage

460 Volts

3 Phase, 9 Lead Motor
Y-Connection

Use of Variable Frequency Drives

Motors -

Motors that are to be operated using a Variable Fre­quency Drive (VFD) must be VFD compatible. At a mini­mum, this must be a Premium Efficiency motor with
Class F insulation. Motors that are not supplied by Loren
Cook Company should have the recommendation of the
motor manufacturer for use with a VFD.

Grounding -

The fan frame, motor and VFD must be connected to
a common earth ground to prevent tran sien t vo ltages
from damaging rotating elements.

Wiring -

Line reactors may be required to reduce over-voltage
spikes in the motors. The motor manufacturer should be

consulted for recommended line impedence and usage of
line reactors or filters, if the lead length between the VFD
and the motor exceeds 10 feet (3m).

Fan -

It is the responsibility of the installing body to perform
coast-down tests and identify any resonant frequencies
after the equipment is fully installed. These resonant fre­quencies are to be removed from the operating range of
the fan by using the “skip frequency” function in the VFD
programming. Failure to remove resonant frequencies
from the operating range will decrease the operating life of
the fan and void the warranty.

Please refer to AVA critical speed table on page 5. Vari­able frequency drives should not allow AVA fans to operate
between the low and the high speeds list.

Wiring Diagrams

Single Speed, Single Phase Motor

Ground A

T-1

T-4

Ground B

L

1

Line
L

2

Wiring Diagrams

3 Phase, 9 Lead Motor

3 Phase, 9 Lead Motor
Delta-Connection

Low Voltage

208/230 Volts

7
6

1

L

1

When ground is required, attach to ground A or B with no. 6 thread forming
screw. To reverse, interchange T-1 and T-4.

To reverse, interchange any 2 line leads.

2 Speed, 2 Winding, Single Phase Motor 2 Speed, 1 Winding, 3 Phase Motor

Ground A

T-1
T-4

Ground B

When ground required, attach to ground A or B with No. 6 thread forming
screw. To reverse, interchange T-1 and T-4 leads.

High Speed

L

1

L

2

Low Speed

Line

1

Together

2

Motor

3

L

1

4

L

5

2

6

Line

L

3

Motor

To reverse, interchange any 2 line leads. Motors require magnetic control.

Single Speed, Single Phase, Dual Voltage 2 Speed, 2 Winding, 3 Phase

Ground A

L

T-5

J-10

Ground B

Link A
Link B

Low Voltage

Line

L

1

T-5

J-10

2

Ground B

When ground required, attach to ground A or B with No. 6 thread forming
screw. To reverse, interchange T-5 and J-10 leads.

Ground A

Link A & B

High Voltage

T

Low Speed

3

Low Speed

T

L

1

Line

L

2

Motor

T
T

T
T

2
1

11
12
13

Low Speed

High Speed
High Speed
High Speed

To reverse: High Speed-interchange leads T11 and T12.
Low Speed-interchange leads T
line leads.

and T2. Both Speeds-interchange any 2

1

Typical Fan Motor/Damper Motor Schematic

High Voltage

460 Volts

9

8
4
2

L3L

2

Low SpeedHigh Speed

789

5
3

456

3

12

L1L

L

3

2

L

1

1

L

2
3

4
5
6

2

L

3

Open

Line

L
L
L

1
2

Line

3

Transformer**

Fan

Motor

Damper

Motor*

Second
Damper

Motor

L3
L2
L1

Transformer**

For 3 phase, damper motor voltage should be the same between L1 and

. For single phase application, disregard L3. *Damper motors may be

L

2

available in 115, 230 and 460 volt models. The damper motor nameplate
voltage should be verified prior to connection. ** A transformer may be
provided in some installations to correct the damper motor voltage to the
specified voltage.

4