Atlas Copco PTS 800 T3 Cud Instruction Manual page 77

Symptom
Air pressure rises above maximum
and causes safety valve to blow off
Compressor overheating
Possible cause
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.
Bypass valve of oil cooler remains stuck in open position.
Corrective action
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.
Remove bypass valve, clean and inspect.
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