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-- 5-9-3) AUTOMATIC MOTOR SPEED REGULATION
(Fig. 3) --
The system controls the speed of the diesel motor according to the compressed air taken
in and consists of: maximum pressure valve (G), suction regulator (B), accelerator control
piston (E), contrast spring (H).
With motor on and the cock (R) fully open, the motor speed is at the maximum and the
suction regulator is fully open.
By slightly closing the cock (R) reduced air consumption is simulated with consequent
increase in pressure in the tank (Z).
On closing the cock (R), the pressure reaches the pre-set value and the maximum
pressure valve (G) opens, allowing compressed air to flow out, which acts on the
accelerator control piston (E) and beneath the suction regulator valve (B).
Being stimulated by this pressure the piston (E) is able to exceed the contrast force of
the spring (H), and by means of a lever system, the motor is proportionally decelerated.
At the same time the suction regulation valve (B) also closed proportionally, thereby
reducing the suction air passage. Therefore with cock (R) closed and with no air
suction, the motor stabilizes at the minimum set speed while the suction valve (B) of the
regulator reaches almost total closure position.
In this stage of the cycle the suctioned air is minimal and it serves to compensate for
any leakage within the circuit itself.
At this stage the maximum final pressure will be indicated on the pressure gauge of the
control panel.
On resumption of air intake stage the maximum pressure valve (G) will start to close up
and it will be totally closed when the pressure value falls to below approx. 1 bar in
relation to the maximum final pressure value.
During this stage the compressor delivers the maximum capacity to the working
pressure as the spring (H), without the contrasting effect of the accelerator piston (E),
accelerates the motor to maximum speed and the suction regulator valve reaches fully
open position.
In the event of use of tools with a consumption exceeding the nominal capacity of the
compressor, a reduction in the pressure will be noted on the gauge, which must
however never be less than 5 bar.
Avoid any sudden opening of the cocks: they cause excessive stress on the oil
separator filter and serious damage to the same.
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Summary of Contents for MDVN 71 AP
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