COOK Automatic Belt Tensioner Supplement I - 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”
BELT IDLER
RT3000 WITH
2 GROOVE “A”
BELT IDLER
RT4000 WITH
2 GROOVE “B”
BELT IDLER
ACE, ACSC, ACRU, VCR, and SRSH Units - Sizes 60 to 490
INSTALLATION, OPERATION, AND MAINTENANCE MANUAL
Automatic Belt Tensioner Supplement I
This publication contains the installation, opera-
tion and maintenance instructions for the Automatic
Belt Tensioner.
Carefully read this publication prior to any installa-
tion 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 publi-
cation 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 (417)869-6474,
extension 166; by FAX at (417)832-9431; or by e-mail at
[email protected].
For information and instructions on special equipment,
contact Loren Cook Company at (417)869-6474. The
Automatic Belt Tensioner uses sealed bearings which do
not require maintenance and contains no user-service-
able parts. Do not disassemble the belt tensioner.
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 ten-
sioner, 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 mount-
ing 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 ten-
sioner 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 car-
riage bolts with 5/16-18 x 1-1/4 wizz bolts. Insert bolts
through motor plate mounting holes and thread 5/16-
18 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
3/4” and still allow motor plate to clear bearing mount-
ing 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 mark-
ing pencil to make an alignment mark on the ten-
sioner 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 ten-
sioner arm counterclockwise (clockwise on sizes
402-490) approximately 1/2” past the mark on the
bearing plate. While holding tensioner at this posi-
tion, tighten mounting bolt fully.
7. Install belt by wrapping belt around tensioner idler
pulley then use both thumbs to hold belt in idler pul-
ley 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 pul-
ley. Check tension by listening for excessive belt
squeal at startup. Repeat steps 6 and 7.
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 applica-
tion, units with counterclockwise rotation point coun-
terclockwise and clockwise rotation point clockwise.
Automatic Belt Tensioner
Cation:
Do not use the top assembly nut to add additional ten-
sion as this may potentially cause damge the ten-
sioner. It must be re-positioned per tensioning
assembly instructions.
Caution:
Do not use the top assembly nut to add additional ten-
sion as this may potentially cause damge the ten-
sioner. It must be re-positioned per tensioning
assembly instructions.