2.8 Troubleshooting
Problem
A
Protective
motor
switch
interrupts
power supply
W Pressure relief does
not function
C
Compressor
not
start
when
switched on.
D
Compressor
starts
up briefly / buzzes
and then switches
off automatically
E
Compressor
continuously
F
Load-relieving valve
is blowing off
G
Switch-off pressure
reached:
relieving
valve
blows
off
switch-on pressure
is reached
Cause
In case of malfunctions (e.g.
overheating;
extension cable too long or
with incorrect cross-section),
the protective motor switch is
tripped.
Power failure / undervoltage in
mains
with
switched on
does
Vessel pressure is higher than
switch-on pressure.
Power supply faulty
Protective motor switch inter-
rupts power supply.
Pressure switch defective
Mains connection cable longer
than permitted or the cross
section is too small
runs
Intake filter badly contami-
nated
Air consumption of compressed
air tools is too high
Leakage at compressor
Excessive condensate in the
tank
Compressed air line leaky
Condensate drain valve is open
or missing
Load-relieving valve leaky
Check valve insert leaky or
load-
defective
Check valve is damaged
until
Remedy
Switch off the compressor. Wait
low
voltage;
a short while. Actuate the protec-
tive motor switch is available.
Switch on the compressor.
Protective motor switch trips
again: switch off compressor.
Disconnect the power supply.
Contact the service partner
Switch off the compressor. It de-
compressor
pressurises. Switch on the com-
pressor
Relieve pressure in the vessel
until the pressure switch is acti-
vated automatically.
Have the power supply checked
by a qualified person (e.g. ser-
vice partner)
See item A.
Have
changed by a qualified person.
Check connection cable length
and
Chap. 2.4.3)
Clean or replace
Check air consumption. Contact
the service partner
Locate leak, contact service part-
ner
Drain
Chap. 2.6.3)
Check the compressed air net-
work, seal leak
Close or replace
Clean or replace
Clean
Chap. 2.6.10)
Replace
UNM STS/STL
the
pressure
cable
cross-section
the
condensate
or
replace
GB
switch
(see
(see
(see
II/5