16
Symptom
Possible causes
Check methods
Possible remedies
No oil discharge.
Breaker trips.
Motor doesn’t
rotate.
・
Blackout or voltage drop.
・
Check the power supply
equipment.
・
Solenoid valve or breaker trips.
・
Reset the Solenoid valve,
breaker.
・
Power supply is disconnected
or has a poor connection.
・
Replace or reconnect the cable.
Overloading.
・
Is power rating adequate for
the operation.
・
Use motor with higher output
rating.
・
Use pump with lower capacity.
・
If you find it difficult to choose
the right motor or pump, please
consult us after checking oil
viscosity, required pressure
and pipe layout.
Pump won’t rotate or
rotate unsmoothly by
hand.
・
Are viscosity and lubricity of the
oil adequate?
・
Rotor galling or foreign object
stuck inside the pump.
・
Is the oil fairly clean?
・
Repair or replace pump.
Loud noise.
Abnormal noise.
・
Suction resistance
is too high
(cavitation).
・
Suction pipe is too
narrow.
・
Suction pipe too
long.
・
Motor speed is too
fast.
・
Suction filter has a
large resistance.
・
Oil viscosity is too
high.
・
Suction lift is too
high.
・
Measure the suction pressure
with vacuum gauge.
・
Cavitation must be occurring if
suction pressure is lower than -
0.03MPa.
・
Make sure that suction
pressure is within -0.03 ~ 0MPa
(Close to atmospheric
pressure).
・
Replace with larger pipes.
・
Make the pipe length shorter
・
Replace with filters in which the
resistance is smaller.
・
Replace with oil with lower
viscosity.
・
Lower the suction lift.
・
The pump is
drawing air
(Airation).
・
Is there foam inside the tank?
・
Is there loose pipe connections?
・
Make sure that air doesn’t enter
the tank, pipes and inside the
pump.
・
Check if returned pipe is under
the oil surface or not.
・
Make sure that the returned
pipe is always under the oil.
・
Misaligned coupling.
・
Check the concentricity of
couplings and shaft alignment.
・
Make sure that the coupling’s
concentricity is within the
specified level.
