USER'S AND
MAINTENANCE
MANUAL
Date:
01/31/2020
Code
MAN D185T4F-DB
ENG
Air Compressor : D185T4F-DB
Revision 03
Copyright © 2014, ROTAIR S.P.A. - All rights reserved
.
This manual is intellectual property of ROTAIR S.P.A.
Its full or partial reproduction is forbidden under any form, on any support and by any means, without the
written authorization by ROTAIR S.P.A.
Page
33/59
9.2
-
1
AUTOMATIC ADJUSTMENT OF THE ENGINE RPM
The system controls the
d
iesel engine
RPM
as a function of the compressed air
used
and includes:
- Max. Pressure valve (4)
- Suction adjustment valve (2)
- Accelerator control piston (5)
1)
With the engine running and the
air
valve (11) fully open, the engine RPM is at the max. value and
the
suction adjuster is fully open.
2)
Partially close the
air
valve (11) to simulate a reduction in the air consumption with subsequent
increase
of the pressure in the tank (A).
3)
When the
air
valve (11) is progressively closed, the pressure reaches the established adjustment
value
and the max. pressure valve (4) controls the compressed air flow out and acts at the same time
on
the accelerator control piston (5) and under the suction adjuster valve (2).
4)
Under the action of such pressure, the piston (5) proportionally decelerates the engine.
5)
At the same time, the suction adjustment valve (2) proportionally closes as well, thus reducing the
passage of the air being taken in. Consequently, with the
air
valve (11) closed and without any air
demand, the engine shall stabilize at the minimum RPM it was adjusted for, while the suction valve
of
the adjuster shall move to an almost total
ly
closed position.
6)
At this stage of the cycle, the intake air is minimal and is used to compensate for any leakages and
internal leakages of the circuit.
7)
The pressure gauge on the control panel shall display the value of the max. delivery pressure.
8)
When the demand for air is resumed, the max. pressure valve (4) shall start closing again and shall
be totally closed once the pressure valve lowers by approx. 1 bar
/
14.4 psi, versus the value of the
max. final pressure.
9)
At this stage, the compressor delivers the max. rate at the service pressure, since the internal spring
of the accelerator piston (5) accelerates the engine up to the max. RPM, and the suction adjustment
valve is in the full open position.
10)
If tools of greater consumption than the rated capacity of the compressor are used, the pressure
gauge shall display a lower pressure, which must never be lower than 5 bar
/
72.5 psi.
11)
Avoid sudden openings of the
air
valves; th
is
generate
s
great stress to the separator filter with
subsequent severe damage to the filter itself.
