Atlas Copco PTS 916 Cd Instruction Manual page 52

PTS 916 Cd
Symptom
Compressor capacity or
pressure below normal
Air pressure rises above
maximum and causes safety
valve to blow off
Compressor overheating
Engine running but
compressor does not load
when 'Load' button is pressed
52
Possible cause
Safety valve or relief valve(s) leaking.
Unloading valve leaking.
Pipe connections leaking.
Working pressure setpoint incorrect.
Air intake throttle valve does not close for some
reason.
Unloading valve malfunctioning.
Insufficient compressor cooling.
Oil cooler clogged externally.
Oil cooler clogged internally.
Compressor oil filter clogged.
Compressor oil level too low.
Fan blade broken or fan drive defective.
Working pressure too high.
Pressure ratio over compressor element(s) too
high.
Electric blow-off valve malfunctioning.
By-pass valve of oil cooler remains stuck in open
position.
Loading solenoid valve inoperative.
Diaphragm of unloader piston perforated or
throttle valve remains closed for some reason.
Control panel 'Load' button inoperative.
Corrective action
Remove and inspect safety valve or relief
valve(s). Replace valve(s) if not airtight after
reinstallation.
Remove and inspect unloading valve. Replace
valve, if necessary.
Check connections and repair if necessary
Adjust setting.
Check position throttle valve.
Disconnect loading solenoid valve from throttle
valve housing and connect independent
compressed-air line to throttle valve housing.
Repeatedly admit air and listen for opening and
closing sound of throttle valve. If sound is not
evident, remove unloader valve assembly,
dismantle and inspect. Replace parts where
necessary.
Remove and inspect unloading valve and blow-
off silencers.
Move unit away from walls; when banked with
other units, leave space between them.
Clean oil cooler.
Consult Atlas Copco.
Replace oil filter.
Before checking compressor oil level, wait
approx. 10 minutes after unit has stopped.
Add correct oil, if necessary. Never overfill.
Check and correct, if necessary.
Adjust setting.
Consult Atlas Copco.
Check interstage pressure. Check functioning of
loading solenoid valve. Replace diaphragm of
blow-off valve if necessary.
Remove bypass valve, clean and inspect.
Check loading solenoid valve and electric wiring.
Replace valve, if necessary.
Remove unloader piston cover and inspect
rolling diaphragm. If in order, check piston for
free axial movement by hand. If jammed, remove
throttle valve housing, dismantle and replace
defective parts.
Consult Atlas Copco.
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Preliminary