EVMS/EVMSL
- 20 -
８
Troubleshooting
Trouble
Cause
Remedy
Motor won’t turn.
Motor growls and
won’t turn
The motor is damaged.
Repair the motor.
Power supply abnormality.
Inspect and repair.
Rotating parts in contact. Rust. Burning.
Manually rotate. Re-assemble. Have repaired by a
specialist workshop.
Foreign material caught in the contacting surfaces.
Remove the foreign material.
Pump operates,
but no water is
discharged.
Water is not
discharged at the
rated capacity.
Pump not primed.
Prime the pump.
Gate valve is closed or half open.
Open the gate valve.
Reverse rotation direction.
Check the rotation arrow, and correct the wiring.
Pump speed too low.
* Motor has wrong number of poles.
* 60 Hz pump used in 50 Hz power supply area.
* Voltage drop has occurred.
* Consult nameplate data and replace motor with
correct one.
* Consult nameplate data and replace correct pump.
* Check the power supply.
Impeller is clogged with foreign matter.
Remove the foreign material.
Piping is clogged with foreign matter.
Remove the foreign material.
Foot valve and/or strainer is clogged with foreign
matter.
Remove the foreign material.
Air is being sucked in.
Inspect, repair suction piping and shaft seal.
Foot valve or end of suction piping is not properly
submerged in the water.
Extend suction piping so that foot valve / end of
piping to be submerged at least 2 times deeper than
the diameter of the piping.
Leakage from discharge piping.
Inspect, repair.
Impeller is corroded.
Check the fluid, change material.
Impeller is worn.
Replace the impeller.
Wear ring is worn.
Replace wear ring.
Large loss in the piping.
Review the plan.
Suction head is too high for the pump.
Discharge head is too high for the pump.
Review the plan.
High fluid temperature or volatile fluid.
Review the plan.
Cavitation.
Consult with EBARA.
Water is
discharged,
but stops.
Not primed sufficiently.
Sufficiently prime the pump.
Air is being sucked in.
Inspect, repair suction piping and shaft seal.
Air is trapped inside the suction piping.
Refit the piping.
Suction head is too high for the pump.
Review the plan.
Overload (over
current) occurs.
Voltage has dropped or phase imbalance is large.
* Head is low. Too much water flow.
* 50 Hz pump in a 60 Hz region.
* Consult nameplate and replace motor with correct
one.
* Consult nameplate and replace correct pump.
Head is too low. Discharge capacity is too high.
Turn down discharge valve to adjust to prescribed
capacity.
Bearing is damaged.
Replace bearing.
Rotating parts in contact. Shaft is bent.
Consult with EBARA.
Fluid specific gravity, viscosity is too great.
Review the plan.
Bearing heats up
Bearing is damaged.
Replace bearing.
Pump is operated for prolonged period at shut-off
pressure.
Stop shut-off pressure operation.
Pump vibrates.
Loud operation
noise.
Bearing is damaged.
Replace bearing.
Discharge capacity is too high.
Turn down discharge valve to adjust to prescribed
capacity.
Impeller is clogged with foreign matter.
Remove the foreign material.
Reverse rotation direction.
Check the rotation arrow, and correct the wiring.
Pump is operated for prolonged period at shut-off
pressure.
Stop shut-off pressure operation.
Rotating parts in contact. Shaft is bent.
Consult with EBARA.
Cavitation.
Consult with EBARA.
Piping vibrates.
Rectify the piping.
More leakage from
the shaft seal.
Mechanical seal is damaged.
Replace mechanical seal.
Suction pressure is too high.
Review the plan.