FAULT FINDING
51
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Compressor overheats.
Low oil level.
Top up the oil level and check for leaks.
Dirty or blocked oil cooler.
Clean the oil cooler fins.
Incorrect grade of oil.
Use Doosan recommended oil.
Defective by-pass valve.
Check the operation of the element and replace if necessary.
Recirculation of cooling air.
Move the machine to avoid recirculation.
Reduced cooling air from fan.
Check the fan and the drive belts. Check for any obstruction
inside the fan cowl.
Excessive oil present in
the discharge air.
Blocked scavenge line.
Check the scavenge line, drop tube and orifice. Clean and
replace.
Perforated separator element.
Replace the separator element.
Pressure in the system is too low.
Check the minimum pressure valve.
Safety valve operates.
Operating pressure too high.
Refer to
SPEED AND PRESSURE REGULATION ADJUST-
MENT
in the
MAINTENANCE
section of this manual.
Incorrect setting of the regulator.
Adjust the regulator.
Faulty regulator.
Replace the regulator.
Inlet valve set incorrectly.
Refer to
SPEED AND PRESSURE REGULATION
ADJUSTMENT
in the
MAINTENANCE
section of this manual.
Loose pipe/hose connections.
Check all pipe/hose connections.
Faulty safety valve.
Check the relieving pressure. Replace the safety valve if faulty.
DO NOT ATTEMPT A REPAIR.
Oil is forced back into
the air filter.
Incorrect stopping procedure used
Always employ the correct stopping procedure. Close the
discharge valve and allow the machine to run on idle before
stopping.
Faulty inlet valve.
Check for free operation of the inlet valve(s).
Machine goes to full
pressure when started.
Faulty load valve.
Replace the valve.
Machine fails to load
when the load switch is
Faulty load valve.
Replace the valve.
when the load switch is
pressed.
Faulty switch.
Test switch
pressed.
Loose pipe/hose connections.
Check all pipe/hose connections.