
Troubleshooting
16 Tips for operators and service technicians
Any repairs exceeding routine maintenance may only be carried out by qualified personnel or our
service.
Prior to working on the unit or in case of danger, disconnect it from the mains.
Error
Possible cause
Remedy
Compressor will not start
No power supply voltage. On
three-phase units: one phase is
missing or not connected (gen-
eration of a humming sound)
❯
Check the mains fuse; if nec-
essary, switch the circuit
breaker back on. If the fuse is
defective, replace it. Check
the mains voltage.
Undervoltage or overvoltage
❯
Measure the supply voltage;
call an electrician if necessary.
Relief valve defective, unit starts
up against pressure
❯
Check that the relief valve dis-
charges after switching off the
unit. Free up the movement of
the relief valve or replace it.
Mechanical sluggishness of a
unit (piston is stuck); motor pro-
tection has tripped
❯
Switch the unit off and dis-
connect it from the power
supply, remove the fan hood
of the blocked compressor
and rotate the fan wheel. If
this is not possible, replace
the piston and cylinder or the
complete unit.
Humming noise from motor
Motor capacitor is defective
❯
Replace the capacitor.
Compressor does not switch
off
Wrong size of compressor, air
intake too high
❯
Calculate the air requirement
(this can be up to 50 l/min per
treatment unit), if necessary
install a larger compressor.
Leak in the compressed air sys-
tem
❯
Locate and seal the leak.
❯
Inform a service technician.
Defective membrane drying unit
❯
Check whether there is an
increased flow of air at the fil-
ter housing of the membrane
drying unit (bottom), if neces-
sary replace the membrane
drying unit.
Compressor switches on from
time to time even though no
air is being taken for a con-
sumer unit
Leak in the compressed air sys-
tem
❯
Locate and seal the leak.
❯
Inform a service technician.
Troubleshooting
5152100003L02 1910V001
39
EN