Sonic 350, Installation And Operation Manual

Page: 19 / 26

©Copyright 2010-Sonic Air Systems Inc.
Page 19 of 26
4. Belt Tension Adjustment
Notes: 1
.Always adjust the tension on a brand new belt to the values prescribed in tables 4 and 5 under the column
“New Belt Tensioning Force”
2 .Subsequent to an operating time of 2500 hours, the belt is considered used and it is necessary to readjust the
tension using the values prescribed in tables 4 and 5 under the column “Used Belt Tensioning Force”.
3 .Always check and adjust belt tension when sprocket alignment correction was necessary.
4 .Always check and adjust belt tension when the belt is fluttering and excessive vibration is detected at a
frequency equal to belt RPM. For the belt P/N 12708 used with the Sonic 350 and which is 1750 mm long,
the speed of rotation is calculated as follows:
RPM
belt
=.046 x Diameter
Motor Sprocket
x RPM
Motor
Motor sprocket diameter must be accounted in inches.
4.1 Tools required
- 1-1/8 in. open wrench (used at jack-screw hex nut)
- 15/16 in. socket wrench (used at sliding bracket hex bolts)
- cross-recessed (Phillips) screwdriver (used at belt guard button head screws)
- Straight Edge 3 ft. long (used at sprocket alignment)
- Belt Tension Tester (Sonic P/N 12817)
4.2 Read all safety procedures (see page 3) before starting any of the following steps.
4.3 Remove belt guard by loosening the six cross-recessed head screws holding it to the structure. Slide
the belt guard away from the structure (see Fig.7).
4.4 Loosen the four hex bolts 1-1/2 turns (do not remove) that are locking the blower support bracket to
the motor (see Fig.8) so that it will easily slide guided by the 4 bolts that are holding it to the motor.
Also loosen the 3/4 in. hex lock nut of the jackscrew.
4.5 Rotate the jackscrew hex nut clockwise in order to raise the blower bracket support and to tension the
belt.
4.6
The Goodyear Tension Tester includes (2) orings to measure inches of span and pounds of force. Set
the inches of span to 26" and set the pounds of force oring to "0 lbf". By placing a straight edge
along the belt face, take the force measurement at the midpoint of the belt span: Place the tester at the
midpoint of the belt span and press on the plunger of the tester until the "deflection" of the belt
reaches the 26" inches of span oring. Now read the oring on the force scale to determine belt tension.
A new belt (0-2500 hrs of use) requires 22-24 lbf, a used belt (2500+ hrs of use) requries 16-17 lbf.
Use the jack screw mechanism to increase or decrease the tensioning force as required.
4.7 Once proper tension is achieved, tighten the 3/4" hex nut of the jack screw and tighten the four (4)
hex bolts that hold the blower support bracket to 100 +/- 10 ft-lbs.