4.4 Operating modes and control modes
4.4.1 Operating modes
The machine operates in the following modes:
■ LOAD
─ The inlet valve is open.
─ The engine runs at maximum speed.
─ The compressor block delivers compressed air.
■ MODULATING
─ With the help of a control valve (the proportional controller) the degree of opening of the
inlet valve is steplessly varied in response to the air demand.
─ The load and fuel consumption of the engine rises and falls with the air demand.
─ The compressor block delivers compressed air.
■ IDLE
─ The inlet valve is closed.
─ The control valve opens, allowing pressure in the oil separator tank to be applied to the inlet
valve.
─ Compressed air then flows in a closed circuit through the compressor block, the oil separa‐
tor tank and the control valve.
─ The pressure in the oil separator tank remains constant.
─ The engine runs at minimum speed.
■ STANDSTILL (shut down)
─ The inlet valve closes.
─ The venting valve opens to de-pressurise the machine.
─ The engine stops.
4.4.2 PART LOAD control
The control system regulates the volume of air generated to match the actual demand. The ma‐
chine keeps the working pressure constant by varying the volume of compressed air delivered,
thereby matching the air demand.
With the help of a mechanical control valve (the proportional controller), the opening and closing of
the inlet valve is continuously varied in relation to the actual air demand. The compressor block
provides compressed air for connected consumers.
This stepless delivery regulation minimises fuel consumption of the engine. Motorbelastningen og
drivstofforbruket stiger/faller med trykkluftbehovet.
4
Design and Function
4.4
Operating modes and control modes
34
Service manual Portable compressor
M122
No.: 9_6974 20 E
RAMIRENT
