Faults
4.2
General faults
Page 46
Operating instructions for S 40-3...S 150-3 series screw compressors
Compressor system
does not start up
No electric power to compressor
Check electrical connection
Fuses are defective
Check the mains fuses and control fuses and replace if necessary
Compressor system has not
vented properly
Check unloading valve and replace, if necessary
Voltage fluctuations in the elec-
trical mains power supply
Ensure constant voltage
Compressor oil is very viscous
due to low ambient temperature
Heat up the compressor system (additional heater available as an
optional accessory)
Oil in suction filter
Minimum pressure non-return
valve is leaking
Check the minimum pressure non-return valve and replace,
if necessary
Suction regulator is leaking
Check the suction controller and replace, if necessary
Cutout triggered by emergency-
off switch
Normally switched off with
O
-key
Excessive oil consump-
tion
Drain line is blocked
Dismantle and clean drain line
Defective oil separator element
Check oil separator and replace, if necessary
Oil filling level too high
Drain off oil
Safety valve blows
Operating pressure setting
altered from original setpoint
Set operating pressure to maximum permissible pressure of the
screw compressor
Defective safety valve
Replace safety valve
System pressure does
not decrease when
switching off
Venting valve does not open
Check venting valve and replace, if necessary
Non-return valve is leaking
Examine non-return valve and replace, if necessary
Fault
Possible cause
Rectification
