Hardi Mercury Series, Instruction Book

Page: 46 / 114

3 - Description
46
Gearbox
The HF540, HF540D and HF640D blowers have a two-speed gearbox
with neutral position.
Upper pos: High speed
Middle pos.: Neutral
Lower pos.: Low speed
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DANGER! Do not attempt to engage or disengage the speed
with the PTO in operation.
HF 640D Turbines
The centrifugal blower units contain a galvanised steel turbine. The
difference between the single model and the double model is that
the double provides the same power as two single turbines
combined.
The position of the blades in this type of turbine is fixed. Their angle
cannot be changed like in axial fans.
The turbines are allowed to turn at a maximum of 540 r.p.m.
The clutch is at the centre of the turbines, which ensures smooth
startup and stops - see section “Clutch” for further information.
Clutch (All blower types)
The clutch is integrated at the centre of all the fan models and will
ensure a smooth start-up and stop of the fan. The clutch design may
vary from model to model, but the functioning and maintenance is
the same.
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WARNING! The clutch is a vital part in the blower unit. Poor
condition could cause the blower unit to break or explode.
The condition of this part should be regularly checked. Please
carefully read the section on its ‘Maintenance’.
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DANGER! The clutch is one of the most important parts in the
blower unit in terms of safety. Make sure that it is in perfect
conditions (i.e. that it is not blocked, etc.) Otherwise, it could
cause the blower unit to explode.