V-Belt Drive Installation; Belt Tension - Kruger ADA Series General Instructions Manual

V-BELT DRIVE INSTALLATION

 Remove the protective coating from the end of the fan shaft and assure that it is free of nicks and
burrs.
 Check fan and motor shafts for parallel and angular alignment.
 Slide sheaves on shafts – do not drive sheaves on as this may result in bearing damage.
 Align fan and motor sheaves with a straight-edge or string and tighten.
 Place belts over sheaves. Do not pry or force belts, as this could result in damage to the cords in
the belts.
 Adjust the tension until the belts appear snug. Run the unit for a few minutes (see section on
unit start-up) and allow the belts to "set" properly.
 Switch off the fan, adjust the belt tension by moving the motor base. When in operation, the
tight side of the belts should be in a straight line from sheave to sheave with a slight bow on the
slack side.
 Aligning sheaves
with a straight edge

BELT TENSION

Proper belt tension is important for long belt life. Too much tension puts excessive loads on the belts and the
bearings, reducing the lives of both components. Not enough tension allows belt slippage which generates
heat and drastically reduces the life of the belt.
Belt tensioning gauges can be used to determine whether the belts are tensioned properly. A chart that
comes with the gauge specifies a range of force required to deflect the belts a given amount based on the
centre distance of the sheaves and the belt cross section. The belts are properly tensioned when the force
required to deflect the belt, the specified amount falls within this range.
If a belt tensioning gauge is not available, re-tension the belts just tight enough so that they do not squeal
when starting the fan. A short "chirp" is acceptable; a squeal lasting several seconds or longer is not
acceptable.
Before starting the fan after tensioning the belts, recheck the alignment and realign the sheaves if necessary.
New belts may stretch a little at first, so recheck belt tension after a few days of operation.
.
Proper
Belt tension indicator
applied to mid-centre
distance.
Offset Pigeon- Toed Angle