Possible reasons
Insufficient lubrication (Cut-out due to oil pressure limiter (if fitted) or damage to sliding surfaces and bearings)
insufficient oil, oil migration
• large plant volume
• insufficient gas velocity, rising pipelines
oil viscosity too low due to high dilution with refrigerant
• compressor during off cycle colder than evaporator
• too much refrigerant
• leaking solenoid valve in liquid line
• insufficient liquid accumulation at start
• too little suction gas superheat or hunting
during operation
oil temperature too high
• leaking / defective working valves
• worn piston rings
oil no longer capable of lubricating
• contaminated by wear particles or foreign matter
• chemically decomposed, increased moisture content
oil pump / oil regulation valve defective
suction pressure at oil pump inlet too low
• oil filter blocked
• suction filter blocked
Component damage (Compressor does not run despite demand and drive, only heavily or with unusual noises)
Components in compressor defective
• overloading, liquid slugging
• lack of lubrication
• usual wear
Magnetic clutch defective
• magnet overloaded
• bearing overloaded, excessive belt tension,
too short clcok cycles
Shaft seal leaking
• lack of lubrication
• overheating (hardening, cracks, oil coke)
• strong vibration (loose clutch, belt drive not
aligned, irregular drive)
• excessive belt tension
KW-540-1
Measures, recommendations
• supplement oil charge, check over longer operating time
• check over longer operating time with minimum compressor
speed, change pipe runs if necessary
• solenoid valve in liquid line and check valve in discharge
gas line may be necessary
• reduce to minimum level
• repair / exchange
• fit "swan neck" in suction line, if required fit liquid accumulator
• superheat minimum 6..7 K, correct bulb position or fixing if
required
• see "safety cut-out"
• exchange, check pistons and cylinder liners
• check magnetic plug, oil filter and base plate,
change oil (repeatedly if required), cure cause
• check for acid / moisture content, check for coke deposits
(valve plate) and Cu plating (sliding surfaces, valve plate).
Change oil and drier (repeatedly if required), cure cause
(renew hose connections which have increased porosity)
• repair / exchange
• clean, oil change, with possible wear, exchange compressor
• clean, cure cause
• repair / exchange, cure cause
• repair / exchange, cure cause
• repair / exchange
• exchange, cure cause (e.g. loss of voltage due to
corroded connecting terminals)
• exchange, cure cause
(oil leakage up to approx. 0,05 cm
• exchange, see "insufficient lubrication" for guide
• exchange, cure cause
• exchange, cure cause
• adjust belt tension
3
/h within tolerance)
25