Subject to change without notice.
10
KWV-20G*ATA**
REV — 02/26/20
however; the motors may also be sealed from
servicing so if they are, then the bearings are
permanently lubricated. Check for oil plugs at the
top of the motor on each end of the motor over
the bearing area. If there are oil plugs, the motor
requires oiling. Each motor requires ten (10)
droplets of SAE 5W 30 oil after every 2-3 years of
normal operation.
CAUTION: Over lubricating will cause the
bearing to overheat and could
cause the bearing seal to blow
out .
Belt Tensioning
Excessive belt tension is the number one cause
for blower and motor bearing failure. Proper
belt tension and pulley alignment are essential
for trouble free operation. Insufficient deflection
indicates that the belt tension is entirely too
tight, and if not loosened somewhat, noise
due to excessive vibration, premature bearing
failure, shortened belt life, and a reduction in fan
performance may result.
Deflection
is the amount
the belt gives when force is applied, usually by
finger, to the belt at the approximate center point
to the belt span. Tight belts may also overload the
motor and cause the efficiency drop considerably
or even premature motor failure as well.
Belt
Span
is the distance in inches between the drive
shaft center point and the fan shaft center point.
Refer to Figure 7 – Belt Tensioning below.
Figure 7 – Belt Tensioning
Excessive deflection is an indication that the belt
is not tight enough. If not corrected, slippage may
occur causing loss of blower speed and belt failure.
The belts will glaze then crack or even break due
to increased temperatures caused by slippage.
Belts may slip during start-up, but slipping should
stop as soon as the fan reaches full speed. For
proper tensioning, an excellent method to use is
listed in the equation below. Belt span is in inches.
Deflection = Belt Span
64
Check the sheave alignment to make sure that
the sheave faces are in the same plane. Check
this by placing a straight edge across the face
of the sheaves. Any gap between the edge and
sheave faces indicates misalignment.
CAUTION: This method is only valid when
the width of the surfaces between
the belt edges is the same for
both sheaves . When they are not
equal or when using adjustable
pitch pulleys, adjust so that the
belts have approximately equal
tension . Both shafts should be
at right angles to the belt . Check
the setscrew and/or bushing bolt
tightness .
Belts tend to stretch somewhat after installation.
Recheck belt tension after several hours of
operation.
Summary of Contents for KWV-20
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