Doosan 12/154 Operation & Maintenance Manual page 98

94 FAULT FINDING
FAULT CAUSE
Air discharge capacity Engine speed too low.
too low.
Blocked air cleaner.
High pressure air escaping.
Incorrectly set regulation system.
Compressor overheats. Low oil level.
Dirty or blocked oil cooler.
Incorrect grade of oil.
Defective by-pass valve.
Recirculation of cooling air.
Reduced cooling air from fan.
Excessive oil present in Blocked scavenge line.
the discharge air.
Perforated separator element.
Pressure in the system is too low.
Safety valve operates. Operating pressure too high.
Incorrect setting of the regulator.
Faulty regulator.
Inlet valve set incorrectly.
Loose pipe/hose connections.
Faulty safety valve.
Oil is forced back into Incorrect stopping procedure used.
the air filter.
Faulty inlet valve.
Machine goes to full Faulty load valve.
pressure when started.
Machine fails to load Faulty load valve.
when the load switch is
Faulty switch.
pressed.
Loose pipe/hose connections.
12/154
REMEDY
See "Engine speed too low".
Check the restriction indicators and replace the element(s) if necessary.
Check for leaks.
Reset the regulation system. Refer to SPEED AND PRESSURE
REGULATION ADJUSTMENT in the MAINTENANCE section of this manual.
Top up the oil level and check for leaks.
Clean the oil cooler fins.
Use Doosan recommended oil.
Check the operation of the element and replace if necessary.
Move the machine to avoid recirculation.
Check the fan and the drive belts. Check for any obstruction inside the fan
cowl.
Check the scavenge line, drop tube and orifice. Clean and replace.
Replace the separator element.
Check the minimum pressure valve.
Refer to SPEED AND PRESSURE REGULATION ADJUSTMENT in the
MAINTENANCE section of this manual.
Adjust the regulator.
Replace the regulator.
Refer to SPEED AND PRESSURE REGULATION ADJUSTMENT in the
MAINTENANCE section of this manual.
Check all pipe/hose connections.
Check the relieving pressure. Replace the safety valve if faulty.
DO NOT ATTEMPT A REPAIR.
Always employ the correct stopping procedure. Close the discharge valve
and allow the machine to run on idle before stopping.
Check for free operation of the inlet valve(s).
Replace the valve.
Replace the valve.
Test switch.
Check all pipe/hose connections.