AUTO BELT TENSIONER
Figure 18 — Motor/Pulley, Tensioner, Disc
and Belt
Figure 19 — Tensioner and Belt Showing Tension
Alignment Marks
Blades removed for clarity of detail
For the MNBCDD model, the Auto Belt Tensioner comes from the factory mounted and preset for adequate belt
tension. If further tensioning is required, loosen the 3/8” bolt holding the tensioner to the tensioner bracket. Then,
using a 15/16” wrench, rotate the tensioner assembly such that the alignment mark is between mark 1 and 2 on
the idler arm (see Figure 19). Re-tighten the 3/8” bolt. Turn the blade assembly by hand to insure free rotation.
Do Not Over Tension The Belt
. This will cause premature belt and bearing failure. To check that the belt tension
is not too high, place a finger midway between the fan pulley and motor pulley and push inward about 1/2”. The
force required to do this
is not
to exceed 5 pounds.
If an Auto Belt Tensioner is ordered for use with an Model MNEFDD fan, use the instructions included in the ABT
packaging for proper installation and use.
NOTE: The Auto Belt Tensioner comes standard with Model MNBCDD, and is an optional accessory for Model
MNEFDD.
Front
View
Mark 2
Mark 1
Alignment mark
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