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The list we present below simulates most possible problems and causes that may result in a halt or incorrect operation of the compressor.
Some procedures to solve the problems are simple, which allows the user, through the reading of the Electronic Interface display, to solve
them without the need of specialized Technical Assistance.
However, if the problem remains after the corrective actions described below, contact the nearest SCHULZ AUTHORIZED DEALER.
OCCASIONAL DEFECTS
PROBABLE CAUSES
SOLUTION
Compressor will not start.
Note:
The compressor may be
powered down for the action
of the pressure switch and
will automatically start (if that
is the cause, the pressure is
high and the pressure switch
prevents the restart)
Phase or electric power missing.
Check the wiring and protection fuses.
Voltage missing in the control.
Check the protection fuse and circuit breaker of the command.
With voltage on the command, the light (if it is ok) must turn
on.
Motor overload relay of the air end or fan tripped.
Reengaged it and check the cause by restarting
the compressor.
Overtemperature.
Wait for some minutes until going back to the ideal operating
temperature. Wait for some minutes until the voltage returns to
the command and light 8 turn on (Figure 11.1).
Thermal protector went off.
Coil of the contactors burnout.
Check the coils of the contactors.
Other causes: Wires with loose or broken contacts.
ON button defective.
Check this component by following the wiring scheme; find
where the interruption that prevents the start of the compressor
is located.
Emergency stop button activated.
Unlock the button by turning it.
The compressor starts and
immediately turns off.
Overload relay tripped,
Identify the cause, eliminate it and check the adjustment
range of the relay.
Installation not in compliance with the related standard
Check the current and discrepancies between phases.
Check the cause and resize the cables if necessary.
Phase missing
(installation fuse burnout)
Check if proper fuses are used.
Check the cause for the fuse burnout.
Power supply cables of motor loose in the input
or output of the contactors.
Check the conditions of the cables and insulations and
retighten them if necessary.
Overload relay with defect or contact of contactors worn out.
Check the contacts of the contactors K1, K2, K3.
If they are good, observe the overload relay.
Overheating of the
compressor.
Oil filter clogged.
Replace it
Air filter clogged
Replace it
Oil level low.
Check the cause and change the oil, using LUB SCHULZ/LUB
SCHULZ SYNTHETIC.
Compressor inlet filter clogged.
Replace it
Radiator clogged.
Clean it.
Thermostatic valve not working.
Request the presence of the Technical Assistance.
Intermittent noise at the start.
The contactors seem not to
activate.
Voltage drop in the power supply.
Installation not in compliance with the related standard.
Recheck the dimensioning of the power supply cables,
observing the distance from the power supply (transformer).
Verify how much the voltage drops in the control at the moment
of start.
Check discrepancy between the phases.
Check if there are no command wires loose.
Fan burnout.
Check the cause and eliminate it. If the problem persists,
request the presence of the Technical Assistance.
Contactor of the fan defective.
17. FAILURE DIAGNOSTICS