COOK AC User Manual

AC

Centrifugal Roof and Wall Exhausters

®

INSTALLATION, OPERATION AND MAINTENANCE

This publication contains the installation, operation and
maintenance instructions for standard units of the AC-
Centrifugal Roof and Wall Exhausters.

• ACE-D / ACE-B

• ACW-D / ACW-B / ACW-HP / ACW-XP

• ACRU-D / ACRU-B / ACRU-HP / ACRU-XP

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

Loren Cook AC catalog 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 and instructions on special equipment,
contact Loren Cook Company at 417.869-6474.

Rotating Parts & Electrical Shock Hazard:

Disconnect electric power before working on unit.
Follow proper lockout / tagout procedures to ensure

the unit cannot be energized while being installed or
serviced.

A disconnect switch should be placed 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.

Grounding is required. All field-installed wiring must
be completed by qualified personnel. All field­installed wiring must comply with National Electric
Code (NFPA 70) and all applicable local codes.

Failure to follow these instructions could result in
death or serious injury.

Handling

Lift the fan by the shipping
carton or lifting lugs provided
under top cap. NOTICE! Never

lift by the shaft, motor or
housing.

Storage

If the fan is stored for any
length of time prior to installation,
store it in its original shipping
crate and protect it from dust,
debris and the weather.

Lifting Lugs

Installation

If the fan was delivered with the motor unmounted, see
the maintenance section for belt and pulley installation.

If the fan was purchased as a wall mount unit and a
grease terminator or grease trough was not purchased, a 1­1/16 inch diameter drain hole should be drilled at the bottom
side of the fan for drainage.

Code requirements and environmental effects

The attachment of roof mounted fans to the roof curb
as well as the attachment of roof curbs to the building
structure must exceed the structural requirements
based on the environmental loading derived from the
applicable building code for the site. The local code
official may require variations from the recognized
code based on local data. The licensed engineer of
record will be responsible for prescribing the correct
attachment based on construction materials, code
requirements and environmental effects specific to
the installation.

Failure to follow these instructions could result in
death or serious injury.

Receiving and Inspection

Immediately upon receipt of an AC fan, carefully inspect

the fan and accessories for damage and shortage.

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

• Check dampers (if included) for free operation of all
moving parts.

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

Wall Exhauster Installation

If your fan is a wall exhauster, a mounting template is
shipped with the fan. Use the template to locate the
necessary lag screws or anchor bolts on the wall. The fan
can then be lifted and attached easily. Secure with lag
screws, anchor bolts, or other suitable fasteners.

Damper Installation

If your fan is supplied with dampers, follow the directions
below. If your fan does not include dampers, proceed to
Belt and Pulley Installation.

1. Place the damper inside the curb or inside the duct
work. Ensure the damper will open freely for the correct
direction of the airflow.

2. Secure to curb at the damper shelf.

3. Drill hole in the curb shelf for conduit needed for motor
wiring.

4. Operate the dampers manually to ensure the blades
move freely.

5. Install fan over curb while aligning the conduit location
with the conduit hole in the curb.

Wiring Installation

NOTICE! 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.

(See page 3 for diagram)
Upblast units have two wiring conduits. The vertical

conduit comes plugged. The horizontal conduit is directly

above the vertical conduit

For Units Without A Junction Box:

An approved metal field wiring compartment must be
secured to the unit with two screws in order that the box
does not rotate. All wires must be protected from abrasion
where they enter and exit the wiring compartment. The
green ground wire from the motor must be secured under
the green ground screws inside the field wiring compartment
using a closed loop connector. Complete connections in
accordance with the wiring diagram on the motor.

For Units With A Junction Box:

Pull wires through the appropriate conduit. Protect wires
from abrasion where they enter the field wiring compartment
and complete connections in accordance with the diagram
on the motor.

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.

NOTICE! 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 switch to promote safety (i.e.,
red tape over a closed switch).

1. Remove the top cap which covers the motor assembly
by unlatching the snap clips.

2. For internal wiring, run the electrical wire and conduit
through the opening drilled in the damper shelf (refer to
Damper Installation), then through the wiring conduit in

the ventilator base to the motor compartment. For
external wiring, run the wires through the horizontal
conduit on upblast units, or under top cap in downblast
units.

3. Pull the wires through and complete the wiring.

Single Speed, Single Phase Motor

Ground A

T-1
T-4

Ground B

2 Speed, 2 Winding, Single Phase Motor

Ground A

T-1
T-4

Ground B

Single Speed, Single Phase, Dual Voltage

Ground A

T-5

J-10

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.

Link A
Link B

Low Voltage

3 Phase, 9 Lead Motor
Y-Connection

Low Voltage

208/230 Volts

4

5

6

3

1

9

728

L2L

L

1

To reverse, interchange any 2 line leads.

High Voltage

12

3

2 Speed, 2 Winding, 3 Phase

To reverse: High Speed-interchange leads T11 and T12.
Low Speed-interchange leads T1 and T2. Both Speeds-interchange any 2 line leads.

2

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

L

1

Line
L

2

When ground required,
attach to ground A or B
with No. 6 thread forming
screw. To reverse, inter-

L

1

change T-1 and T-4

Line

leads.

L

2

Ground A

L

Line

L

High Speed

Low Speed

1

T-5

J-10

2

Ground B

3 Phase, 9 Lead Motor
Delta-Connection

460 Volts

456

789

3

L2L

L

1

3

Low Voltage

208/230 Volts

8

7

4

6

2

1

L

1

9
5
3

L

3L2

Link A & B

High Voltage

460 Volts

789
456

12

L1L

L

2

L

1

Line

L

2

3

3

Typical Damper Motor Schematic

Fan

Motor

Transformer**

Damper

Motor*

For 3 phase, damper motor voltage should be the same between L1 and L2.
For single phase application, disregard L3. *Damper motors may be 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.

Second
Damper

Motor

L3
L2
L1

Transformer**

Final Installation Steps

1. Ensure fasteners and set screws, particularly fan
mounting and bearing fasteners are tightened according
to the recommended torque shown on the table below.

2. Inspect for correct amperage with an ammeter and
correct voltage with a voltmeter.

3. Ensure that all accessories are installed.

4. Test the fan to be sure the rotation is the same as

indicated by the arrow marked ‘Rotation’.

NOTICE! Do not allow the fan to run in the wrong
direction. This will overheat the motor and cause
serious damage. For 3-phase motors, if the fan is
running in the wrong direction, check the control
switch. It is possible to interchange two leads at this
location so that the fan is operating in the correct
direction.

5. Inspect wheel-to-inlet clearance. Wheels may shift in

shipment. To realign wheel-to-inlet, shift upper bearing
so there is an equal radial clearance between the wheel
and inlet. Refer to wheel to inlet clearance on page 6.

Recommended Torque for Setscrews/Bolts (IN/LB)

Setscrews

Recommended

Key Hex

Size

No.10 3/32” 28 33 3/8”-16 240

1/4” 1/8” 66 80 1/2”-13 600

5/16” 5/32” 126 156 5/8”-11 1200

3/8” 3/16” 228 275 3/4”-10 2100

7/16” 7/32” 348 384 7/8”-9 2040

1/2” 1/4” 504 600 1”-8 3000
5/8” 5/16” 1104 1200 1-1/8”-7 4200
3/4” 3/8” 1440 1800 1-1/4”-7 6000

Across

Flats

Torque Inch-lbs.

Min. Max. Size

Hold Down Bolts

Wrench

Torque (inch-

lbs)

Operation

1. Lock out all the primary and secondary power sources.

2. Inspect and tighten fasteners and setscrews, particularly

fan mounting and bearing fasteners Refer to Torque
chart.

3. Inspect belt tension and pulley alignment. Refer to Belt

and Pulley Installation, page 4.

4. Inspect motor wiring. Refer to Wiring Installation.

5. Ensure belt touches only the pulleys.

6. Rotate the wheel to ensure it rotates freely.

7. Ensure fan and ductwork are clean and free of debris.

8. Close and secure all access doors.

9. Restore power to fan.

Start-up

Turn on the fan. In variable speed units, set the fan to its

lowest speed. Inspect for the following:

• Direction of rotation

• Excessive vibration

• Unusual noise

• Bearing noise

• Improper belt alignment or tension (listen for squealing)

• Improper motor amperage or voltage

If a problem is discovered, immediately shut the fan
off. Lock out all electrical power and check for the cause
of the trouble. Refer to Troubleshooting on page 6.

Inspection

Inspection of the fan should be conducted at the first 30
minute, 8 hour and 24 hour intervals of satisfactory
operation. During the inspections, stop the fan and inspect
as instructed.

30 Minute Interval

Inspect bolts, setscrews, and motor mounting bolts. Adjust

and tighten as necessary.

8 Hour Interval

Inspect belt alignment and tension. Adjust and tighten as
necessary.

24 Hour Interval

Inspect belt tension. Adjust and tighten as necessary.

Maintenance

Establish a schedule for inspecting all parts of the fan. The
frequency of inspection depends on the operating conditions
and location of the fan.

Inspect fans exhausting corrosive or contaminated air
within the first month of operation. Fans exhausting
contaminated air should be inspected every three months.

Regular inspections are recommended for fans exhausting
non-contaminated air.

Regular inspections of the Grease Terminator 2 are
recommended. Depending on the amount of grease
discharged through the fan, the Grease Terminator 2 should
be changed every 30 to 45 days to ensure proper operation.
Any buildup of grease is easily seen during a visual
inspection of the clear canister. However, if the Grease
Terminator 2 becomes saturated, grease will no longer be
absorbed.

It is recommended the following inspections be conducted

twice per year.

• Inspect bolts and setscrews for tightness. Tighten as
necessary. Refer to Torque chart.

• Inspect belt wear and alignment. Replace worn belts with
new belts and adjust alignment as needed. Refer to Belt
and Pulley Installation, page 4.

• Bearings should be inspected as recommended in the
Conditions Chart.

• Inspect for cleanliness. Clean exterior surfaces only.
Removing dust and grease on motor housing assures
proper motor cooling.

3

Fan Bearings

NOTICE! The fan bearings are provided
prelubricated. Any specialized lubrication instructions
on fan labels supersedes information provided herein.
Bearing grease is a petroleum lubricant in a lithium
base conforming to a NLGI #2 consistency. If user
desires to utilize another type of lubricant, they take
responsibility for flushing bearings and lines, and
maintaining a lubricant that is compatible with the
installation.

A NLGI #2 grease is a light viscosity, low-torque, rust­inhibiting lubricant that is water resistant. Its temperature
range is from -30°F to 200°F and capable of intermittent
highs of 250°F.

Bearings should be relubricated in accordance with the

condition chart below.

Conditions Chart

RPM Temp °F Greasing Interval

Up to 1000

1000 to 3000

Over 3000
Any Speed < -30 Consult Factory

Any Speed > 200 1 week

For moist or otherwise contaminated installations; divide the interval by a
factor of 3. For vertical shaft installations divide the interval by a factor of 2.

-30 to 120 6 months
120 to 200 2 months

-30 to 120 3 months
120 to 200 1 month

-30 to 120 1 month
120 to 200 2 weeks

For best results, lubricate the bearing while the fan is in
operation. Pump grease in slowly until a slight bead forms
around the bearing seals. Excessive grease can damage
seal and reduce life through excess contamination and/or
loss of lubricant.

In the event that the bearing cannot be seen, use no
more than three injections with a hand operated grease
gun.

Motor Bearings

Motors are provided with prelubricated bearings. Any
lubrication instructions shown on the motor nameplate
supersede instructions below.

Direct Drive 1050/1075,1200,1300 &1500 rpm units use a
prelubricated sleeve bearing that has a oil saturated
wicking material surrounding it. The initial factory lubrication
is adequate for up to 10 years of operation under normal
conditions. However, it is advisable to add lubricant after 3
years. Use only LIGHT grade mineral oil or SAE 10W oil up
to 30 drops. If the unit has been stored for a year or more it
is advisable to lubricate as directed above. For units in
severe conditions, lubrication intervals should be reduced
to half.

Motors without sleeve bearings (as described above) will
have grease lubricated ball or roller bearings. Motor
bearings without provisions for relubrication will operate up
to 10 years under normal conditions with no maintenance.
In severe applications, high temperatures or excessive
contaminates, it is advisable to have the maintenance
department disassemble and lubricate the bearings after 3
years of operation to prevent interruption of service.

For motors with provisions for relubrication, follow

intervals of the table below.

Relubrication Intervals

NEMA Frame Size

Service

Conditions

Standard 3 yrs. 6 months 2 yrs. 6 months 1 yr. 3 months

Severe 1 yr. 3 months 1 yr. 3 months 6 months 1 months

Up to and

including 184T

1800 RPM

and less

Over 1800

RPM

213T-365T 404T and larger

1800 RPM

and less

Over 1800

RPM

1800 RPM

and less

Over 1800

RPM

NOTICE! Motors are provided with a polyurea mineral
oil NGLI #2 grease. All additions to the motor bearings
are to be with a compatible grease such as Exxon Mobil
Polyrex EM and Chevron SRI.

The above intervals should be reduced to half for vertical
shaft installations.

Motor Services

Should the motor prove defective within a one-year period,
contact your local Loren Cook representative or your nearest
authorized electric motor service representative.

Changing Shaft Speed

All belt driven ventilators (5HP or less) are equipped with
variable pitch pulleys. To change fan speed, perform the
following:

1. Loosen setscrew on driver (motor) pulley and remove
key, if equipped.

2. Turn the pulley rim to open or close the groove facing. If
the pulley has multiple grooves, all must be adjusted to
the same width.

3. After adjustment, inspect for proper belt tension.

Maximum RPM with standard or reenforced wheel

ACE-B ACRU-B &

Size

Standard Reinforced Standard Reinforced Standard Reinforced

60 1981 ­70 1941 -

80 1806 ­100 2013 - 2002 ­120 1669 - 1671 ­135 1574 - 1574 ­150 1519 - 1520 - 1952 ­165 1296 - 1295 - 1728 - 2508
180 1513 - 1546 - 1829 - 2396
195 1348 - 1353 - 1570 - 2100
210 1190 - 1197 - 1626 - 2126
225 1043 - 1086 - 1435 - 1879
245 885 - 901 - 1185 1234 1616
270 752 - 766 - 1025 1049 1656
300 837 861 837 877 980 1046 1391
330 716 734 716 748 830 912 1182
365 624 648 624 659 735 872 1132
402 539 550 539 560
445 463 465 463 473
490 360 396 360 403
540 347 401 -

ACW-B

Speed Reduction:

Open the pulley in order that the belt rides deeper in the

groove (smaller pitch diameter).
Speed Increase:

Close the pulley in order that the belt rides higher in the
groove (larger pitch diameter). Ensure that the RPM limits of
the fan and the horsepower limits of the motor are
maintained.

ACRU-HP &

ACW-HP

ACRU-XP

&

ACW-XP

4