20
Excessive oil in discharge air.
1.
Blocked or dirty inlet air
filters.
2.
Overfilled with oil.
3.
Low oil viscosity.
4.
Excessive duty cycle.
5.
Blocked or damaged
crankcase breather.
6.
Damaged or worn intake
valves, piston rings, pistons
and/or cylinders.
1.
Clean or replace air filter
elements.
2.
Drain oil down to high level
mark.
3.
Replace with correct oil.
4.
Reduce air demand or use
larger or additional
compressor(s).
5.
Clean or replace crankcase
breather.
6.
Replace components or
entire compressor pump.
Water in discharge air.
1.
No fault, this is normal
operation. Condensation
quantity will increase with
duty cycle and humidity.
1.
Install dryer and/or filter in
discharge line. Install
automatic tank drain valve
or manually drain air tank
more often. Revise
distribution piping system to
ensure proper condensation
drainage.
Compressor does not switch off
and safety valve discharges.
1.
Faulty pressure switch.
2.
Faulty safety valve. Note:
use tank pressure gauge to
help diagnose fault.
1.
Replace pressure switch.
2.
Replace safety valve.
Low suction or air blowing out at
air filter inlets during pumping
mode.
1.
Damaged or worn
compressor pump inlet
valves and/or blown cylinder
head gaskets.
1.
Replace compressor pump
inlet valves and/or cylinder
head gaskets.
No Short discharge of air from the
pressure switch after reaching
cut-out pressure or being manually
switched off.
1.
Faulty unloader valve in
pressure switch.
2.
Blocked or damaged
unloading line.
3.
Blocked or faulty non-return
valve.
1.
Replace unloader valve or
complete pressure switch.
2.
Clean or replace unloading
line.
3.
Clean, repair or replace
non-return valve.
Short initial discharge of air from
240v pressure switch during
pumping mode after starting with
nil or low pressure in air receiver
tank.
1.
Correct function of the “soft
start” pressure switch
unloading valve to reduce
motor starting current.
1.
Nil (no fault)
Continuous discharge of air from
the pressure switch after reaching
cut-out pressure or being manually
switched off.
1.
Faulty non-return valve.
1.
Repair or replace non-return
valve.
Continuous discharge of air from
pressure switch during pumping
mode.
1.
Faulty unloader valve in
pressure switch.
1.
Replace unloader valve or
complete pressure switch.
Air receiver tank does not hold
pressure when compressor is off
and discharge outlet valve is
closed.
1.
Faulty non-return valve.
2.
Air leaks.
1.
Repair or replace non-return
valve.
2.
Tighten, refit or replace
leaking connections or
components.
External oil discharge from
compressor pump.
1.
Oil leaks
1.
Tighten, refit or replace
leaking connections or
components.
Oil appears “milky” in sight glass.
1.
Water contamination in oil.
1.
Replace oil and move
compressor to less damp or
humid location.
Oil appears black in sight glass.
1.
Graphite carry-over from cast
iron material (initial oil fill
only).
2.
Oil dirty and/or overheated
(initial or subsequent oil fill).
1.
Replace oil.
2.
Replace oil and check for
compressor pump
overheating.
