6-1
6.
Troubleshooting
Caution
If there is any failure that cannot be resolved, immediately stop operation,
and contact us or your service company. When contacting us/them,
please inform us/them of the information shown on the nameplate and the
conditions of the failure.
Table 6-1-1: Troubleshooting
Failure
Probable cause
Measures
When the power is
turned on, the pump
does not start.
Failure or loss of the power supply
Check the connection or turn on the power again.
The power fuse is blown.
Replace the power fuse.
The overload protection device of the motor has tripped. Reset the overload protection device.
The power voltage is too low.
Contact the power company.
The motor has failed.
Replace the motor.
The shaft seal part has seized up.
Ask the specialized vendor for investigation.
The bearing is rusty
The pump or the piping is clogged with foreign objects.
The overload
protection device of
the motor trips.
The overload setting is too low.
Properly set the overload device of the motor.
The cable connection is loose or a failure has occurred. Tighten the cable connection or replace it.
The power fuse is blown.
Replace the power fuse.
The motor does not operate because the pump is
clogged with foreign objects.
Ask the specialized vendor for investigation.
Rotating parts touch the other part or are damaged.
The winding of the motor has a defect.
Replace the motor.
The power voltage is low.
Contact the power company.
The discharge rate is too large.
Throttle the sluice valve on the discharge side to adjust the
discharge rate.
The pump operates,
but water is not fed.
No or insufficient priming of the pump
Fill the pump with liquid.
The sluice valve on the suction discharge side is closed. Open the sluice valve.
The piping is clogged with foreign objects.
The pump is clogged with foreign objects.
Check and clean the suction pipe or the discharge pipe.
Ask the specialized vendor for investigation.
The foot valve or the check valve is clogged or has a
failure.
Replace the foot valve or the check valve.
Piping work has been performed with the dust caps
attached to the suction or discharge side.
Remove the dust caps.
Air is trapped in the suction pipe or the pump.
Release air.
The rotation direction of the motor is wrong.
Change the connection of the motor.
The performance of
the pump is unstable
or insufficient.
The pressure on the suction side of the pump is too
low.(Cavitation)
Check the suction conditions.
The suction pipe or the pump is partly clogged.
Check the pump or the suction pipe.
The flow rate of the pump is larger than the specified
value.
Throttle the sluice valve on the discharge side to adjust the
discharge rate.
The suction pipe leaks the liquid or sucks air.
Check the suction conditions.
Release air from the pump.
The rotation direction of the motor is wrong.
Change the connection of the motor.
The screws of the bypass plug are loose.
(ASVM(N)(G) 25, 32 series)
Tighten the screws of the bypass plug.
The impeller and the liner ring are worn.
Ask the specialized vendor for investigation.
When the power is
turned off, the pump
rotates backward.
The foot valve or the check valve has failed.
Check and replace the foot valve or the check valve.
The suction pipe leaks.
Repair or replace the suction pipe.
Vibration and noise
Cavitation has occurred in the pump.
Reduce the flow rate or check the suction conditions.
The discharge rate is too large.
Throttle the sluice valve on the discharge side to adjust the
discharge rate.
The positioning of the main shaft of the pump is wrong. Adjust the main shaft of the pump.
The bearings of the motor are damaged.
Replace the bearings.
An inverter is used.
Change the operation frequency or the carrier frequency.
