Common problems and solutions of water pumps

1) Reasons for the non-rotation or non-effluent of the sewage pump and its removal method

1, the switch is disconnected or the fuse is blown, check whether the power supply voltage or the use of the head is in line with the provisions, if not, it should be adjusted.

2, power supply power or phase loss, check the power supply voltage like power failure and troubleshooting.

3. The impeller is stuck by debris, and the debris in the impeller flow passage is removed.

4. The stator windings are burnt out. Find out the reasons and parts of the burnt stator windings and return them to the factory for maintenance.

5. If the mechanical seal or bearing is damaged, the mechanical seal or bearing should be cleaned or replaced.

2) Check the mechanical seal of the water pump in the process of use, the mechanical seal will cause more than the standard leakage due to wear, it must be carried out at this time.

Repair and replace rubber sealing components of underwater axial flow pump, and replace or grind the dynamic and static sealing rings according to the damage situation.

3) Reasons for the large or small flow of sewage pump

1, sewage pump flow is large or small reasons: sewage pump selection problem

Sewage pump selection is a very important work, if the selection is improper, will lead to sewage pump in the submersible axial flow pump work flow is large or small, head is high or low, material resistance to wear, corrosion, etc., which not only in use can not meet the production requirements, but also low efficiency, short life, resulting in waste and loss.

2, sewage pump flow is large or small reasons: the use of failure

The use of the flow beyond the range of use, will make sewage pump motor overload;

For submersible sewage pump, the flow is too large, the pump shaft power increases, will make the motor overload;

For axial flow pump, the flow is too small, the pump shaft power increases, will make the motor overload.

The treatment method is appropriate to adjust the valve, the sewage pump or mixed flow pump to reduce (to the axial flow pump increase) the flow, so that the pump flow submersible axial flow pump volume in the normal range of use.

Only after the sewage pump has solved the above problems can it be used, otherwise long-term use may cause the submersible pump motor to burn down.

4) Requirements for selection of sewage pump

1, the pH value of the sewage in the pool, determine the pH value, choose the appropriate material, such as 304, 316, 316L, fluorine plastic, cast iron, etc.

2, determine the voltage, is 380V or 220V;

3, determine the sewage temperature;

4, determine the sewage density;

5. Determine the pipe diameter of sewage pump;

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6. Calculation of pipeline loss: Calculate the pipeline loss according to the length of the pipeline and the number of elbows and valves.

7, according to the demand to determine the flow of stainless steel sewage pump;

8, sewage pump head calculation: pump head = water surface to outlet vertical height difference + pipeline loss + outlet pressure + margin of safety (10%)

9, according to the sewage pump diameter, flow, Yang Cheng choose the appropriate model;

10, determine the installation mode: fixed, mobile.

5) The pump motor can start, but it stops after a few seconds:

First, the contactor self-protection contact can not be closed normally;

The second is that the starting torque of the pump motor is too large (generally caused by the mechanical jamming, which depends on the specific situation), leading to the operation of low-voltage comprehensive protection or thermal relay;

Third, water pump motor winding or cable grounding or short circuit, resulting in air switch trip.

If you have other technical problems, please contact our technical engineer: 13585159616

6) Preparation and inspection of submersible pump before use

Submersible pump before use, should be the most submersible pump, switch box cable and other equipment underground as follows comprehensive inspection: 1, submersible pump before use, should check the motor stator around the submersible axial flow pump group to the ground insulation resistance, its value is generally greater than or equal to 50 meohm.

2. Before the submersible pump is used, a special protection switch or overload protection switch with specifications should be installed so that the submersible pump can be protected reliably and effectively when it fails in use, without damaging the stator winding of the submersible pump motor, or even damaging the whole submersible pump motor.

3. Before the submersible pump is used, the shell should be reliably grounded. The yellow and green two-color grounding wire with grounding mark in the lead line of the submersible pump should be reliably grounded.

4. Before the submersible pump is used, the oil-filled submersible pump and dry submersible pump should be checked whether the internal motor or the sealed oil chamber is full of oil;

The flushing submersible pump should be filled with clean water.

5. The submersible pump should generally be lifted vertically, not used horizontally on the ground, and should not be put into the mud to prevent the motor damage caused by the poor heat dissipation of the telephone.

6, the submersible pump should not be dehydrated operation.

7, three-phase submersible pump before use, should check the rotation direction is correct.

8. When moving or handling the submersible pump, the power supply should be cut off first, and the cable should not be dragged by force.

7) Reasons why the water pump cannot be started

1. After starting, the motor does not turn without any sound, which indicates that the circuit is blocked. At this time, we should check whether the power circuit is broken and whether the insurance is fused.

2. After starting, the motor does not rotate and is accompanied by a "buzzing" sound.

In this case, stop and check immediately.

The reasons are as follows:

(1) One phase of the water pump power line or stator winding is disconnected, resulting in phase-deficient operation.

(2) the voltage is too low, the reason may be that the power supply voltage is too low, the cable is too long and the section is too small, which should be checked one by one.

(3) there is a foreign body in the pump body, the bearing is damaged and stuck, and the phenomenon of "wrap shaft" and "bite to death" occurs. At this time, the pump should be checked and cleaned.

(4) Starting capacitor failure, capacitive pump, when connected to the power supply can hear the buzzing sound, but the submersible pump motor does not turn.

At this time, if the impeller is gently touched, the submersible pump can immediately rotate, it can be judged that the capacitor has been damaged.

8) Insufficient head of water pump

The outlet pressure of the pump is not sufficient.

There are many reasons for this failure: cavitation of the pump, serious wear after long-term use of the impeller, the speed of the supporting motor submersible axial flow pump is lower than the speed required by the pump, etc., will cause the reduction of the pump head.

Increase the pump inlet liquid level height or reduce the pump installation position, can avoid cavitation.

Replace the worn impeller and choose the motor matching with the pump, which is also one of the methods of troubleshooting.

The pump is not selected properly and needs to be replaced with a suitable model.

9) Reasons for weak outlet water pump and small flow

1. Check whether the voltage reaches the rated voltage.

2, check whether the pump rotor is flexible.

3. Check whether the pump is reversed and adjust the phase sequence.

4. The power supply cable of submersible pump is too thin or too long.

10) Causes and solutions of insufficient pump flow

Water pump flow insufficient reasons: impeller reversal;

Solution: Adjust the power wiring.

Reasons for insufficient pump flow: insufficient voltage, low speed;

Solution: Adjust the voltage.

Water pump flow insufficient reasons: impeller flow channel, pipeline is blocked;

Solution: Remove the foreign body.

Reasons for insufficient pump flow: serious wear of impeller or sealing ring;

Solution: replace the impeller.

11) Maintenance of submersible sewage pump

1. If the submersible sewage pump control cabinet shows leakage protection, check whether the mechanical seal is damaged.

2. If the submersible sewage pump control cabinet shows overtemperature protection, check whether there is enough lubricating oil in the oil chamber, or check whether the concentration of the medium is too high, or the head required by the user is too low.

3. Regularly check the insulation resistance of the winding to the casing in the cooling state should be less than 50 meohm.

4. Check regularly whether there is enough lubricating oil in the oil chamber. If the oil in the oil chamber is emulsified or there is water precipitation, the N10 oil and mechanical seal should be replaced in time.

12) Matters needing attention in the operation of submersible sewage pump

1, often check the integrity of the cable, so as not to be damaged in the process of transportation caused by leakage phenomenon, the water-filled submersible pump should also pay attention to the cable joint, to prevent leakage in the cable joint.

2, pay attention to the voltage change, when the voltage exceeds ± 10% of the rated voltage, do not start the pump.

3. The power must be cut off before moving the submersible sewage pump. The submersible sewage pump shall not enter the pool when it is running, so as to avoid personal accidents caused by electricity leakage.

4. It is strictly prohibited to run the motor without phase.

If the fuse is found to be blown, you should check the reason before continuing to use.

No arbitrary thickening of the fuse is allowed.

5. In the case that the submersible sewage pump is not equipped with automatic safe when it is used, the submersible sewage pump should be managed by a special person in use.

If any abnormal phenomenon is found, stop the machine immediately and check the reason.

Troubleshoot the problem before starting the operation.

6, the submersible sewage pump to prevent the entrance blockage.

13) Inspection work before installation of sewage pump:

1. Check whether the manual, certificate and nameplate carried by the sewage pump are consistent with the pump.

2. Check whether the parts are damaged or the fasteners are loose during transportation, and deal with them first.

3. Check whether the sewage pump cable is damaged or broken.

If damaged, the submersible cable should be replaced in time to avoid leakage. The cable section and current should match.

4. Check the isolation oil chamber to see if it is full of mechanical oil. If not, it should be filled up.

5. Before running the sewage pump, the insulation resistance of the motor stator winding to the ground should be checked by megahmmeter, and the insulation resistance should not be less than 50 megahms.

14) What are the basic measures to ensure that the pump equipment is trouble-free?

1. Timely cleaning, refueling, fastening, corrosion prevention and daily routine of the machine pump.

2. Strictly implement the operating rules of the post and use the water pump correctly.

3. Timely discovery, repair or replacement of damaged parts.

4. Provide operation and maintenance skills and strengthen the sense of responsibility.

5, put forward reasonable suggestions to improve the lack of pump design.

15) Routine maintenance of water pump

1. Check whether the power cord is damaged every day, and absolutely prohibit the underwater water pump with leakage.

2. Check whether the pump body is damaged every day to ensure that the motor does not leak when working.

3. After the end of the operation, the sundries attached to the pump should be cleaned up in time and the pump should be flushed clean.

4, in order to ensure the normal operation of the submersible pump, it must be carried out in accordance with the instructions.

5, the pump before use, must be used, check the motor insulation resistance by megger are the lowest value shall not be less than 50 m Ω.

16) The main technical requirements of sewage pump are:

1, sewage pump rated power should not be greater than 1.3 times of the pump shaft power.

2. The sewage pump is allowed to change in the range of -6%~+10% under the specified flow.

3, Under the rated voltage, the maximum torque of the motor guaranteed value: for single-phase motor should not be less than 1.8 times the rated torque, for three-phase motor should not be less than 2 times the rated torque.

4, Under the rated voltage, the guaranteed value of the motor's blocking current: for single-phase resistance-starting motor, it should not exceed 10 times the rated current, and for other motors, it should not exceed 7 times the rated current.

5, sewage pump completely into the medium should be able to stipulate the head range times continuous operation.

At the rated power, the temperature rise limit of the motor stator winding (resistance method) should be: 75 kilohm for the edge of the E-class absolutely submerged axial flow pump;

80 kΩ insulation for grade B;

100 kΩ insulation for class F.

6. The insulation resistance of the motor stator winding to the housing is not less than 50 megohm in cold state and not less than 1 megohm in hot state.

7, rated power in 7.5 kW and below the pump should use direct start, rated power in 7.5 kW above the pump should use indirect start, when the under-pressure 15%, the pump can start load.

8, sewage pump should have overheating or over-current protection device.

9, sewage pump frequency is 50 Hz, single-phase power supply voltage of 220 volts, three-phase power supply of 380 volts, voltage fluctuation range of 0.9~1.1 times the rated voltage.

10, sewage pump in the water into the depth of 0.5~8 meters.

17) The maintenance of sewage pump should be noted as follows:

1, sewage pump continuous or cumulative working time of more than 1000 hours after the submersible axial flow pump should check whether the fasteners are loose, mechanical seal is good.

If abnormal should be repaired, but also check whether the mechanical seal oil is turbidity, such as turbidity should be replaced in time.

2, sewage pump should be cleaned up in time after use.

When the sewage pump is put out of the water after use, the impeller part of the sewage pump should be cleaned up in time, the accumulation in the sewage pump should be eliminated, dried and put in a dry and ventilated place. It should not be soaked in water for a long time, so as not to reduce the service life of the pump.

3, sewage pump damage should be repaired in time.

When the sewage pump is damaged, it should be repaired by professionals in time. In the case of not understanding the internal structure, it should not be easy to open and repair by itself. Remember to repair the sewage pump with electricity in the process of use.

4, sewage pump after one year, according to the surface corrosion, repaint rust prevention, two years after use should be a comprehensive repair and maintenance.

18) Matters needing attention in the use of WQ sewage pump

1. When the WQ sewage pump is put into the collecting tank or slides into the collecting tank along the decoupled guide rail, it must pull the pump lifting cable chain and slowly send it down. It is not allowed to drop or pull the pump cable to send the pump down.

3. Before using the auto-installation system, the dirt in the pool must be cleaned up.

The use of mobile installation, the bottom of the collecting tank mud is too thick or debris too much, should be lifted from the bottom of the pump more than 30 cm.

4, WQ type sewage pump before the use of wiring trial, put down from the lower observation, the impeller anticlockwise to correct;

Standing on power, clockwise shaking is correct.

When reversing, any two phases in the three-phase power supply can be reversed. It is strictly prohibited to reverse operation, otherwise the pump will vibrate and the water volume will be reduced and the injection will be weak. The reverse operation will be destroyed for more than 200 hours.

5, WQ type sewage pump motor is water-cooled, liquid level automatic on/off pump point should be located at the top of the pump.

In the process of long-term use, no matter automatic or manual, it is not allowed to start frequently, generally not more than six times per hour is appropriate.

6. The power cord of WQ sewage pump must be connected with the matching electric control box or the matching thermal relay protection, and shall not be directly connected with the main power supply. When touching the pump in installation, maintenance and replacement, the power supply shall be cut off first, and live operation is strictly prohibited.

7, no matter single pump or double parallel, can only use vertical and horizontal dual-tap door type or Y-type ball check valve, otherwise it will cause check valve blockage or double pump circulating water.

8. No matter the use of decoupled guide rail or rubber hose, the free drop of pump cable chain and power line should not exceed 20cm. Excessivelength will be cut off by suction pump inlet.