Evaporative Coolers
– Maintenance Tips
Changing Your Cooler
Belts
You might at first think that
changing your evaporative cooler belt is easy. Why
spend your valuable time reading about it? Keep
reading; because this information could not only
give more time between belt changes it could also
possibly save bearing problems down the road, and
hundreds of dollars in costly repairs.
Tips
to Keep in Mind
Most residential
coolers originally come with a 4L V-belt (ex. 4L
55). These work
just fine
but, they usually stretch out after a period of a
short time. When the belt stretches to the point
where squealing is heard you often notice that it
still looks to be in pretty good shape. Most people
use the motor mount adjustments to tighten the belt
and everything is fine. Or is it? Usually by the
time it stretches again it must be changed. When it
comes time to replace
it, many
owners neglect to readjust the motor mounts back to
their original positions. This is where the trouble
starts! When a brand new belt is put on the tension
will be set far higher than the manufacturer’s
suggested tension setting. Most people think the
belt will just stretch again right? Big Mistake!
This puts far more wear on the bearings and cause
premature bearing and motor failure. Changing a
bearing on a cooler that has had moisture in it for
several years can be a nightmare!
Expert Suggestions
To
make your life easier, here are two suggestions.
First, instead of changing the original belt with
another 4L V-belt, try using an A V-belt (ex. A 55).
The A belt width is the same and they are for
heavy-duty wear. In sizing the A belt you must keep
in mind that the A belt is always two sizes smaller
than the 4L belt. For example, a 4L 50 belt means
that this belt is 50 inches around if you measured
the outside length. For an A belt that is 50 inches
outside diameter the belt would be an A 48, because
these belts are measured on the inside. So you
always need the A belt to be two numbers smaller
than the 4L belt to have the same size belt. These
belts are a little more expensive but, they usually
last twice as long with less readjusting.
Second, make sure, with either belt you use, that
you set the pulley tension to the original setting.
To test tension, press on the belt half way between
the motor sheave and the fan pulley. A 3lb. force
should deflect the belt 3/4 of an inch. Usually only
two things will cause premature belt wear. Either
the belt tension is too tight or the pulleys are not
in line with each other. In most cases you can
remove the back cooler panel and check the pulley
alignment visually. Another way is to get a straight
edge, like a yardstick and placing it against the
larger blower pulley and see how it lines up with
the motor sheave. If both of these are correct you
will get more life out of your evaporative cooler
belts.