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FAN SPEED CONTROL
The pulley installed on the fan motor(s) is of the variable diameter type.
The machines ordinarily come with a median transmission ratio, so the nominal value can be obtained in most
cases of installations.
For other uses requiring the spreading of channelled air, filters, etc. - i.e. for all the solutions requiring changes
in the aeraulic resistance - the air flow should be adjusted to the nominal value, if needed.
This check can be performed precisely with specific tools or approximately (with a good approximation) by
checking (when the burner is calibrated on the nominal thermal capacity) the thermal gradient between the
air outlet temperature and the air inlet temperature and comparing it with the specifications of the "TECHNICAL
DATA" paragraph.
In any case, you should check that the fan rotation direction matches the direction indicated by the arrow on
the worm-conveyor. If there is a three-phase electric motor, to change the direction of rotation simply invert
a phase of the supply line without tampering with the wiring of the electrical panel.
It is also necessary to make sure that the absorption of the motor does not exceed that indicated
on the plate adjusting, if necessary, the number of rotations of the fan to obtain this result.
By increasing the primitive diameter of the drive pulley, the number of rotations of the fan and the
electric absorption of the motor increase. By decreasing the primitive diameter of the drive pulley,
the number of rotations of the fan and the electric absorption of the motor decrease.
To change the number of the spins carried out by the fan, perform the following operations:
Type 1
–
2:
•
Loosen the belts tension by unloosing the screw
2
•
Remove the belt
1
•
Using an hexagonal bar spanner
5
, unloose the grains
4
of the sheave
3
movable part.
•
Rotate the sheave of the movable part until the desired original diameter is reached.
•
Firmly tighten the screws
4
at the hub cavity
•
Install the belt
1
and stretch it.
