4.6 Operating modes
4.6.1 Operating modes
The machine operates in the following modes:
■ LOAD:
The inlet valve is open. The airend delivers gas into the gas network.
The compressor motor runs under full load.
■ STANDSTILL:
The inlet valve is closed. The minimum pressure/check valve shuts off the oil separator from
the gas discharge line. The venting valve is open.
The drive motor is stopped.
4.7 Variable speed with frequency converter (SFC)
When the machine runs in LOAD, the frequency converter compensates for deviations between
SETPOINT pressure and ACTUAL pressure by changing the speed of the drive motor and, there‐
by, the airend.
The speed of the airend determines the rate of compressed gas delivery and the absolute working
pressure.
These changes in speed match the gas delivery to the gas consumption and keep system pressure
as constant and as close as possible to the SETPOINT pressure.
This functions within the control range of the machine between minimum and maximum delivery
(V
min
und V
max
).
4.8 Safety Devices
The following safety devices are provided and may not be changed:
■ EMERGENCY STOP control device:
Stops the machine immediately in an emergency situation. The motor remains stopped. The
pressure system is vented.
■ Pressure relief valve:
The pressure relief valve protects the system against excessive pressure. This is factory set.
■ Enclosures and guards for moving parts and electrical connections
Protect against accidental contact.
4 Design and Function
4.6 Operating modes
ESD_2C_10357405_10–LIN_00 E
Service Manual Screw Compressor
ESD 442/14 bar (abs) SFC SIGMA CONTROL 2
29
To Next Page
Loading...
