Download User Manual for Screw Compressors

cause may be an air-end or motor (bearing) damage; call the service company.
6. TROUBLESHOOTING
SYMPTOM
3
4
5
POSSIBLE CAUSE
REMEDY
If the compressor is equipped with standard (electromechanic) control panel,
The compressor can not be switched WYE/DELTA time relay (ZR1) may be defective or wrong adjusted. Check
the time adjustment (approx. 6 seconds) the light/LED indicators. If the 2nd
A from WYE stage to DELTA stage.
(WYE/DELTA motor starter failure.) light/indicator is not lighting/ON or the color of the light is not changing at
the end of WYE stage, the relay is defective and must be changed.
* 11-45 kW : Inlet valve/head may be stuck in closed position.
* 55+ kW : The control air from the solenoid valve can not move the actuator
B Inlet valve defective.
piston (servo cyclinder diaphragm is damaged), call the service company.
Read 2F.
C Minimum pressure valve defective.
*11-45 kW: Check power puppy to then soleoid valve, when the power is
switched to ON you can hear the noise/sound of the solenoid then the cause
may be mechanical problem/damage of solenoid valve diaphragm. If the
Compressor is not
power switching (ON/OFF, opening/closing) noise/sound is not heard, the
producing air
solenoid (the coil) is defective. Change the solenoid (coil) or the complete
(does not run on
solenoid valve if it is required.
load).
*55+ kW: Check power supply to 2 solenoid valves. If power is not supplied
D Solenoid valve defective/plugged.
to solenoids, check Ks relay if the contacts or the coil is damaged or not.
Change the relay if it is damaged. Another possibbe cause is closing failure of
the by-pass solenoid valve (with 2 way NO solenoid valve). Check the
soleoid valve for blockage due to dirt, or damage of solenoid or damage of
diaphragm. Change the solenoid or complete valve if it is required. Check the
control/unloading solenoid valve (with 3 way), change if it is required.
Working pressure switch or wiring is If the compressor is not running on load and the ‘on-load’ lamp is not ON
there is a pressure switch or wiring problem. Check wiring and pressure
defective. (for compressors with
switch, change if it is defective. Check the normally open (auxilary) contact
E electromechanic control panel)
of K2 contactor if it is conducting the power or not.
Electronic control panel (the
By looking on the electrical wiring diagram, check the relay out which
controller unit) or wiring is defective. energizes the control (loading/unloading) solenoid valve (SV1) is OK or not.
Close the shut-off valve on the delivery line, slowly, to ensure the compressor
Air demand is too high (overs the
reaches to maximum working pressure. If you observe the delivery pressure is
A
compressor capacity).
rising and the compressor is unloading at the max. working pressure setpoint,
it means the compsumption/demand is too high (than the capacity).
If you are sure that the compsumption is not more than the capacity, check
Air leaks on the delivery or
possible air leaks on the compressor air pipework (delivery and comsumption
B
consumption line.
line arragements).
Restriction through inlet air filter causes increased running temperature (also
Compressor can
capacity loss). Stop running of the compressor, inspect air filter element and
C Air filter is dirty/blocked.
not reach to the
change (clean) if it is dirty/blocked.
maximum working
This circumstance appears when the inlet valve can not open enough
pressure.
(valve/head is stuck). While compressor is stopped and internal pressure
D Inlet valve defective.
is zero, check the valve/head is full closed and can move backward and
toward easly. Call the service company if the valve/head has a curtail or
an oppress problem.
Also, an abnormal (different) noise will be heard while running of the
Mechanic failure in the air end
compressor with a mechanic failure. If the condensed water in the separator
E
(compressor unit).
tank had not drained periodically, the water might be mixed to oil and
circulated in air end and caused air-end damage. Call the service compnay.
Check the range adjustment of working pressure switch; when the pressure
Working pressure switch is defective. reaches to max. working pressure setpoint, the contact of the pressure switch
(for compressors with
must be switched/change (to open/cut). If the device is not switching, it is
electromechanic control panel)
defective and must be changed. (You can get the switching function more
Compressor does A
easily by adjusting range screw to minimum pressure.)
not unload at
Maximum working (Unloading)
maximum working
If your compressor has electronic control panel, check the max. (unloading)
pressure setpoint is changed/wrong.
pressure (overs the
working pressure setpoint on the menu page of the controller unit (display).
max. working
This circumstance appears when the inlet valve can not close (valve/head
pressure setpoint).
stays open as stuck). While compressor is stopped and internal pressure is
B Inlet valve defective.
zero, check the valve/head is full closed and can move backward and
(please read also
toward easly. Call the service company if the vave/head can not close or
symptom 9)
stays open as stuck.
Read 3-D.
C Solenoid valve defective.
Air leaks on the control air
Check the control air circuit fitttings and connections, tighen if any one is
D
line/circuit.
loose. Change hose or tube if it is defective/damaged.
15