Troubleshooting
Fault
Pump does not
start.
Pump gets too hot.
Power consump-
tion of the motor is
too high.
Pump is too loud.
Pump looses oil.
Oil level in the oiler
drops.
Oil turns dark.
Oil in the pumping
chamber.
Pumping speed of
the pump is too
low.
6 Troubleshooting
28
Possible cause
Motor is connected incorrectly.
Faulty pressure switch.
Oil is too thick.
Motor rotor is malfunctioning.
Pump has seized up: damaged impellers, bearings or
gearwheels.
Ambient temperature is too high or cooling air supply is
restricted.
Pump is working in the wrong pressure range.
Pressure differential is too great.
Gas temperature is too high.
Clearance between casing and impellers is too small due to:
– contamination
– distortion of pump.
Excessive frictional resistance due to contaminated bearings
and/or oil.
Oil level is too high.
Oil level is too low.
Wrong oil has been used.
Bearings are malfunctioning.
Valve of pressure balance line does not open.
See fault “Pump gets too hot”.
Wrong mains voltage supply for the motor.
Motor is malfunctioning.
Oil is too thick
Clearance between casing and impellers is too small due to :
– contamination
– distortion of the pump.
Bearing or gearing is damaged.
Impellers strike the casing.
Rotor runs out of true.
Centrifugal disc lubricator strikes gear lid or oil tube.
Oil pump obstructed or malfunctioning.
Oil leak is visible:
Oil-drain plug is not tight.
Oil-level glass is not tight.
Gearbox cover is not tight.
Oil puddle under the motor, leaky can
No oil leak is visible:
See fault “Oil in the pumping chamber”.
Oil leak is visible:
Outer shaft seal is malfunctioning.
No oil leak is visible:
Inner shaft seal is malfunctioning.
Oil has broken down.
Pump gets too hot.
Oil level is too high.
Oil leaks out of the system.
Pump is not installed on a flat horizontal surface.
Pump has an external leak.
Pump has an internal leak.
Impeller rings are malfunctioning.
Dirt trap in the intake flange is clogged.
Motor is connected incorrectly.
Motor faulty.
Pump or pump system has a leak.
Clearance of impellers is too large.
Bearing is malfunctioning.
Valve of the pressure balance line does not close.
Flow resistance in the intake or discharge line is too high
Remedy
Connect the motor correctly.
Replace the pressure switch.
Change the oil or warm the oil and the pump.
Leybold Service
Leybold Service
Install the pump at a suitable site or ensure
enough cooling air.
Check pressure values of vacuum system.
Check pressure values of vacuum system.
Check the vacuum system.
Clean the pumping chamber.
Ensure that the feet and connecting lines aren’t placing a
strain on the pump.
Exchange oil.
Drain some oil to reach the correct level.
Add oil to reach the correct level.
Drain oil and fill in correct lubricant.
Leybold service
Clean or repair the valve.
See fault “Pump gets too hot”.
Connect the motor to the correct voltage supply.
Repair the motor or exchange it.
Exchange the oil or warm up the oil and the pump.
Clean the pumping chamber.
Ensure that the feet and connecting lines aren’t placing a
strain on the pump.
Leybold service, switch off the pump immediately.
Leybold service, switch off the pump immediately.
Leybold service, switch off the pump immediately.
Leybold service.
Leybold service, switch off the pump immediately.
Drain lubricant, firmly screw in the oil-drain plug
with a new gasket, fill in the correct quantity.
Leybold service.
Replace the O-ring of the gearbox cover.
Leybold service, switch off the pump immediately.
See fault “Oil in the pumping chamber”.
Exchange shaft seals. If the oil loss is only slight, the pump
may still be operated for some time provided the lost oil is
topped up regularly.
Exchange shaft seals. Switch the pump off; oil flows into the
bearing spaces of the pump thereby creating in the bearing
spaces an unacceptably high oil level.
Change the oil.
See fault “Pump gets too hot”; after solving the
problem, change the oil.
Drain lubricant to reach the correct oil level.
Check system.
Install pump correctly.
Check proper fit of oil-fill and oil-drain plugs, replace gaskets
if necessary.
Replace O-ring of the gearbox cover.
Leybold service
Leybold service
Clean the dirt trap.
Connect the motor correctly.
Leybold service
Find and seal the leak.
Leybold service
Leybold service
Clean or repair the valve.
Use intake and discharge lines of sufficient diameter.
Repair
3.3
3.3
5.2
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3.1/5.4
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5.6
3.1/3.4
5.2
5.2
5.2
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5.7
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1.3/3.3
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5.6
3.1/3.4
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5.2
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–
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5.8
5.8
5.2
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5.2
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3.1
3.2/5.2
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5.5
3.3
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–
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4.7
* for repair information, refer to the stated section in the Operating Instructions