COOK Automatic Belt Tensioner Supplement I User Manual

BELT TENSIONER IDENTIFICATION DETAIL

BI-DIRECTIONAL

TENSIONER

DIRECTIONAL ARROW
(SEE RT3000/RT4000
INSTALLATION NOTES)

DIRECTIONAL ARROW
(SEE RT3000/RT4000
INSTALLATION NOTES)

RT1000 WITH

1 GROOVE “A”

RT3000 WITH

2 GROOVE “A”

RT4000 WITH

2 GROOVE “B”

Automatic Belt Tensioner Supplement I

ACE, ACSC, ACRU, VCR, and SRSH Units - Sizes 60 to 490

INSTALLATION, OPERATION, AND MAINTENANCE MANUAL

This publication contains the installation, opera­tion and maintenance instructions for the Automatic
Belt Tensioner.

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

Loren Cook brochure, Automatic Belt Tensioner, pro-
vides 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 [phone]. The
Automatic Belt Tensioner uses sealed bearings which do
not require maintenance and contains no user-service­able parts. Do not disassemble the belt tensioner.

3/4” and still allow motor plate to clear bearing mount­ing bolts. (See Figure 1, page 2) (Does Not Apply To

Size 100)

4. Install belt around all sheaves and rotate tensioner
counterclockwise (clockwise on sizes 402-490) until
belt feels tight and there is light spring pressure.

5. While holding tensioner at this position, use a mark­ing pencil to make an alignment mark on the ten­sioner and the bearing plate so that the tensioner
can be rotated back to the same position after
removing the belt.

6. Remove the belt and then realign the marks on the
tensioner and the bearing plate. Now rotate the ten­sioner arm counterclockwise (clockwise on sizes
402-490) approximately 1/2” past the mark on the
bearing plate. While holding tensioner at this posi­tion, tighten mounting bolt fully.

7. Install belt by wrapping belt around tensioner idler
pulley then use both thumbs to hold belt in idler pul­ley groove and push tensioner idler pulley clockwise
(counter clockwise on sizes 402-490) towards the
driver pulley. Then use index fingers to slip belt over
the driver pulley and the driven pulley.

8. Do not use a screw driver to pry belts onto the pul­ley. Check tension by listening for excessive belt
squeal at startup. Repeat steps 6 and 7.

Installation

1. Set belt tensioner assembly on top flange of bearing
plate and line up with the prepunched mounting hole.
There could be several mounting holes to choose
from. To select the optimum location for the ten­sioner, take the driven sheave and set it on top of the
bearing plate centered on the shaft location. Use the
closest hole to the driven sheave center without the
tensioner’s cylinder interfering with the driven
sheave. With the tensioner centered over the mount­ing hole, bring a 3/8-16 x 1-1/4 wizz bolt up through
the hole and thread it into the bottom of the tensioner.

2. Tighten the mounting bolt finger tight allowing ten­sioner assembly to rotate freely.

3. Align driver and driven sheaves with tensioner idler
pulley. If driver sheave is too high on the motor shaft,
remove motor plate from bearing plate. Replace car­riage bolts with 5/16-18 x 1-1/4 wizz bolts. Insert bolts
through motor plate mounting holes and thread 5/16­18 wizz nuts onto bolts and tighten fully. Now install
motor plate onto upper slots on bearing plate with
extra 5/16-18 wizz nuts. This will move motor shaft up

Cation:

Caution:

Do not use the top assembly nut to add additional ten-

Do not use the top assembly nut to add additional ten­sion as this may potentially cause damge the ten-

sion as this may potentially cause damge the ten­sioner. It must be re-positioned per tensioning

sioner. It must be re-positioned per tensioning
assembly instructions.

assembly instructions.

RT3000/RT4000 Installation Notes:

1. The RT3000 and RT4000 have a directional arrow to
ensure proper installation. The arrow must always
point toward the belt being tensioned. In this applica­tion, units with counterclockwise rotation point coun­terclockwise and clockwise rotation point clockwise.

Automatic Belt Tensioner

Mounting

Bolt

Size 402-490
Belt Tensioner
Installation
(Shown with RT3000
Belt Tensioner and
2 Groove Idler)

Size 120-365

Belt Tensioner Installation

(Shown with RT1000 Tensioner and 1 Groove Idler)

2nd Notch

RT1000 Tensioner

Single Groove
Idler Sheave

Size 100 Belt Tensioner Installation

(Shown without belt installed and

tensioner mounting bolt tully tightened)

FIGURE 1

(Shows motor plate raised 3/4”
by using added slots to allow for
installation of short shaft motors)

(Size 402-490 units with counter clockwise rotation
point clockwise and clockwise rotation point counter
clockwise.) If arrow is pointing the wrong direction,
remove the back of tensioner housing and the spring.
Then flip the spring over, the spring’s center “tail” must
engage the slot in the center shaft. Then push out the
directional arrow piece located in the arm assembly,
and reverse the arrow so it points the opposite way
and snap in place. Note that if the arrow piece is not
pointing in the correct direction, the tensioner cannot
be reassembled.

2. The RT4000 tensioner requires considerable force to
overcome it’s spring tension. If force is so strong that
the procedure given in Note 7 won’t work, use the fol-

lowing procedure. With tensioner mounting bolt
only finger tight, rotate tensioner back so that belts
can be installed easily. Now rotate tensioner arm
until belts begin to tighten and you feel light spring
tension. Hook in provided spanner wrench and
rotate tensioner arm until alignment marks are 3/4
apart. While holding spanner wrench securely at
this position, tighten tensioner mounting bolt fully
and remove spanner wrench.

3. Once installed, the RT4000 tensioner has consid­erable force. The tensioner comes with a limited­use spanner wrench. The spanner wrench must
be used to hold the tensioner base when loosen­ing the mounting bolt.

Limited Warranty

Loren Cook Company warrants that your Loren Cook fan was manufactured free of defects in materials and workmanship, to the extent stated herein. For a period of one (1)
year after date of shipment, we will replace any parts found to be defective without charge, except for shipping costs which will be paid by you. This warranty is granted only to
the original purchaser placing the fan in service. This warranty is void if the fan or any part thereof has been altered or modified from its original design or has been abused, mis­used, damaged or is in worn condition or if the fan has been used other than for the uses described in the company manual. This warranty does not cover defects resulting from
normal wear and tear. To make a warranty claim, notify Loren Cook Company, General Offices, 2015 East Dale Street, Springfield, Missouri 65803-4637, explaining in writing,
in detail, your complaint and referring to the specific model and serial numbers of your fan. Upon receipt by Loren Cook Company of your written complaint, you will be notified,
within thirty (30) days of our receipt of your complaint, in writing, as to the manner in which your claim will be handled. If you are entitled to warranty relief, a warranty adjustment
will be completed within sixty (60) business days of the receipt of your written complaint by Loren Cook Company. This warranty gives only the original purchaser placing the fan
in service specifically the right. You may have other legal rights which vary from state to state.

LOREN COOK COMPANY

Corporate Offices: 2015 E. Dale Street Springfield, MO 65803 417.869.6474

lorencook.com

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Automatic Belt Tensioner Supplement I - March 2010