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6.4 Trouble
checklist
Table 6 Trouble checklist
Problem Cause
Countermeasure
Ref.
(1) Not connected to power
supply
(1) Connect to power supply
3.4
Pump doesn’t
rotate
(2) Power supply side switch is
not on
(2) Turn the power supply side
switch on
4.2
(3) Input power supply voltage
abnormal
(3) Adjust to rated voltage
3.5
(4) overload protection device
tripped
(4) Turn off the power supply,
and leave the pump until it has
cooled down sufficiently (until
the overload protection device
is automatically reset)
4.6
(5) Defective motor
(5) Replace the motor
6.2
(6) Oil viscosity has risen due to
ambient temperature being low
(6) Perform warming operation
4.3
(7) Foreign matter has been
introduced to the pump and
stuck to the rotors, etc.
(7) Disassemble and repair
(replace the cylinder, rotors, etc.)
6.2
(8) The inside of the pump has
rusted due to moisture or
solvents being introduced
(8) Disassemble and repair
(replace the cylinder, rotors, etc.)
6.2
(9) A reactive gas was
introduced, and caused reactive
products to accumulate inside
the pump while it was stopped
(9) Disassemble and repair
(clean the inside of the pump and
remove the reactive products)
6.2
(10) Other pump internal parts
have broken
(10) Disassemble and repair
(replace the broken parts)
6.2
(1) Input power supply voltage
abnormal
(1) Adjust to rated voltage
3.5
Pump rotation is
irregular
(2) Defective pump wiring
(2) Redo pump wiring
3.4
(3) Oil viscosity has risen due to
ambient temperature being low
(3) Perform warming operation
4.3
(4) Foreign matter introduced
into pump
(4) Remove foreign matter,
dissemble and clean
6.2
Pressure doesn’t
drop
(1) Pump is too small for the
vacuum chamber
(1) Select another pump
5.2
(2) Incorrect pressure
measurement method
(2) Measure pressure correctly
5.1
(3) Vacuum gauge not suitable (3) Measure the pressure with a
vacuum gauge that is suitable for
the pressure range and has been
calibrated
5.1
(4) The pipe connected to the
intake is small, or the pipe is too
long
(4) Connect a pipe with a
diameter greater than that of the
intake, and reduce the length of
the pipe between the pump and
vacuum chamber
5.1
