9.4 Other Faults
Fault
Possible cause
Remedy
Machine runs but produces no
compressed air.
Inlet valve not opening or only
opening partially.
Call KAESER service represen‐
tative.
Venting valve not closing.
Call KAESER service represen‐
tative.
Leaks in the pressure system.
Check pipework and connec‐
tions for leaks and tighten any
loose fittings.
Air consumption is greater than
the capacity of the compressor.
Check the air system for leaks.
Shut down the consumer(s).
Hose coupling or maintenance
hose still plugged into the
quick-release coupling on the
oil separator tank.
Remove coupling or mainte‐
nance hose.
Cooling oil runs out of the air fil‐
ter.
Oil level in the oil separator
tank too high.
Drain off oil until the correct lev‐
el is reached.
Inlet valve defective.
Call KAESER service represen‐
tative.
Compressor switches between
LOAD and IDLE more than
twice per minute.
Air receiver too small.
Increase size of air receiver.
Airflow into the compressed air
network restricted.
Increase air pipe diameters.
Check filter elements.
The differential between cut-in
and cut-out pressure too is
small.
Check switching differential.
Cooling oil leaking into the floor
pan.
Hose coupling or maintenance
hose still plugged into the
quick-release coupling on the
oil separator tank.
Remove coupling or mainte‐
nance hose.
Oil cooler leaking.
Call KAESER service represen‐
tative.
Leaking joints.
Tighten joints.
Replace seals.
Cooling oil consumption too
high.
Unsuitable oil is being used.
Use SIGMA FLUID cooling oil.
Oil separator cartridge split.
Change the oil separator car‐
tridge.
Oil level in the oil separator
tank too high.
Drain off oil until the correct lev‐
el is reached.
Oil return line clogged.
Check dirt trap in the return
line.
Tab. 51 Other faults and actions
9
Fault Recognition and Rectification
9.4
Other Faults
58
Service Manual Screw Compressor
ASK T SIGMA CONTROL BASIC
9_5717 20 E
