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5. Troubleshooting
Fault
Cause
Remedy
Difficult to start
up
1. Low power voltage
2. Impeller blocked
3. Voltage decreased too much or cable is too
much thinner
4. Winding burnt
1. Adjust the voltage by 0.9-1.1 times of the rated value
2. Correct the position where the impeller is blocked
3. Select suitable cable
4. Rewind the motor while overhaul
Insufficient flow
1. Too much high head
2. Strainer hood blocked
3. Impeller worn severely
4. Three phase pumps rotate reverse
1. Run the electric pump in the range of rated head
2. Clean and remove the foreign matter
3. Replace the impeller
Sudden stop
1. Switch off or fuse burnt out
2 Impeller blocked
3. Winding burnt out
1. Check and adjust the head or check whether the
voltage is in accordance with the requirement
2. Clean off and remove the foreign matter
3. Rewind the motor
Winding burnt
1. Short circuit due to leakage of the mechanical
seal
2. Impeller blocked
3. Too longer dry running when pump operation
or it starts and stop frequently
4. Pump overload
Dismantle the pump, rewinding according to the original
technical requirements and soak & dry by insulating
paint or send the pump to service agency for repair
Before performing any troubleshooting, make sure the pump has been turned off and all moving components have
stopped rotating. Make sure that the pump cannot be turned on accidentally.
1. Regularly inspect the insulation resistance between the enclosure and the winding of the electric pump, which
shall not be less than 1MΩ when the operating temperature is nearly achieved. Otherwise, the use of the pump
shall not be allowed until the corresponding maintenance measures are taken and the relevant requirements are
met.
2. The pump must be maintained according to the following steps after 2500 hours of normal operation.
a) dismantle the electric pump: check all the wearing parts, such as mechanical seal, bearing, impeller and so on,
the worn or damaged parts must be replaced.
b) Air pressure test: after repairing of the electric pump, the air pressure test must be followed. Under the test
pressure 0.2 MPa, it should last for 3 minutes without any leakage.
c) Replace the oil: take off the M8 screw from the bearing block, inject 10# mechanical oil and fill slowly till oil is full
of the oil cavity.
3. Do not leave the electric pump in water for a long time without using it. It is necessary to run the electric pump
in clean water for a few minutes and make sure that the coagulum in the electric pump is clean both outside and
inside, then dry it and store it in a dry and draughty place after the anti-rust treatment.
4. Maintenance
Warning
