- 10 -
/ PM6
6. Troubleshooting
Problem
Cause
Solution
Insufficient air
quantity
• Filter is clogged
• Too much clearance
• Clean or change filter
• Check clearance
Overload on
electric motor
• Filter is clogged
• Foreign matter are caught in
• Pressure loss in piping is increased (increase in
suction pressure)
• Interference between rotors
• Interference between rotor and casing
• Clean or change filter
• Adjust or replace the rotor and casing
• Check the pressure difference between inlet and
outlet
• Adjust improper rotor clearance. Adjust timing gear
• Make the side clearance larger
Make the clearance between rotor and casing lager
Overheat
• Excessive lubricant in front end cover
• Vacuum pump inlet temperature high
• Too much compression ratio
• Interference between rotor and casing
• Check oil level
• Check suction & discharge pressure
• Search for the cause of interference
Knocking
• Interrelated position between timing gear and rotor
is incorrect
• Improper assembly
• Abnormal rise in pressure
• Damage on gear due to overload or improper
lubricant
• Reposition
• Reassemble
• Search for the cause
• Replace timing gear
Bearing or gear
damaged /
shaft broken
• Improper lubricant
• Lubricant runs short
• Overload
• Change lubricant
• Refill lubricant
• Replace the shaft
* If the troubles are not resolved by the above mentioned actions, the cause may possibly be located in pump operation
condition. In such case, please contact us with the following information.
1. Pump type & model number, serial number, application, etc.
2. Information of piping (suction pressure, strainer, mesh, number of bends, etc.)
Vacuum system check list
Check point
Before Operation
Open cooling water supply valve. Is it flow properly ?
Close vacuum suction. Open discharge line.
Check lubricant colour and level. Is it acceptable ?
Run vacuum pump for few minute before open the suction line.
During Operation
Check vacuum level in full vacuum. Is it normal ?
Check electric condition (voltage & amperage) in full vacuum. Is it acceptable ?
Any abnormal noise ?
Check operation temperature. Is it normal ?
Check lubricant colour and level. Is it acceptable?
Stopping
Run vacuum pump for few minute after closing suction line.
If foreign material is introduced inside of vacuum pump, clean it with cleaning agent.
Discharge cooling water from vacuum pump if the pump is stopped for a long time.
Make sure that suction & discharge line is closed. Make sure power supply is cut off.
3.2001
