4.5.2 Option W1
Prepared for external heat recovery
The cooling oil circuit includes 2 valves regulating the cooling oil temperature.
■ Combination valve: Oil cooler temperature regulator
■ Thermostatic valve: Heat recovery system oil temperature regulator
The oil temperature regulators ensure that the cooling oil is kept at the ideal temperature for ma‐
chine operation.
The thermostatic valve opens first so that surplus heat is released into the heat recovery system. If
the heat recovery system cannot remove sufficient heat, the combination valve opens to additional‐
ly release the cooling circuit via the oil cooler.
Condition:
Combination valve opening temperature = thermostatic valve opening temperature
The heat available for recovery depends on the individual operating conditions of the machine.
Connections are provided for an external system to recover surplus heat.
The thermostatic valve is deactivated when the machine is delivered. The necessary operating ele‐
ment must be installed when installing the heat recovery system.
If necessary, the operating element in the combination valve can be exchanged for one with higher
opening temperature. The opening temperature depends on operating and ambient conditions.
Operating elements are marked with their opening temperature [°C].
If the cooling oil temperature is too low, condensate can form and damage the machine.
➤ Consult KAESER Service on components and layout to ensure proper functioning of the
cooling and heat recovery systems.
4.6 Operating modes and control modes
4.6.1 Operating modes
The machine operates in the following modes:
■ LOAD:
The inlet valve is open. The airend delivers compressed air to the distribution network.
The drive motor runs under full load.
■ IDLE:
The inlet valve is closed. The minimum pressure/check valve shuts off the oil separator from
the distribution network. The venting valve is open.
A small volume of air circulates through the bleed hole in the inlet valve, through the airend
and back to the inlet valve via the venting valve.
The compressor motor runs without load and draws little current.
4
Design and Function
4.6
Operating modes and control modes
30
Service Manual Screw Compressor
ASK T SIGMA CONTROL BASIC
9_5717 20 E