Disruption in the operation of electric motors and electric pumps can be caused by several reasons. In this article, we have tried to collect the most common reasons that may cause electric motors and water pumps to fail and point out practical solutions for each. This is even though these instructions will not include all the problems that may arise during the operation of electric motors and electric pumps, and it is not able to express the details of installation, operation, or maintenance; there will be inevitable problems during the operation of the products, outside of the mentioned cases, and in case of facing these problems, it is necessary to get help from experts in this field. In the following, we will examine some possible problems in the form of questions, the causes related to each question, and finally, we will point out the available solutions to address these problems. It should be noted that most of these cases should be investigated by experts or the manufacturing company itself.

Troubleshooting in electric motors

1- What is the reason for the time-consuming acceleration of the engine?

The presence of a large load can cause the acceleration of the electric motor to take time. Reducing the load will be a good solution in this case.

Disturbance in the rotor can also be another reason for the acceleration of the electric motor. In this case, the rotor must be inspected and replaced if damaged.

Incorrect drive settings may cause the mentioned error. In this case, the settings must be carefully made again.

Low voltage when starting the engine is another cause of this problem. For this reason, the voltage drop and its cause should be checked.

2- Why is the motor rotation direction wrong?

In three-phase motors, the wrong phase sequence can lead to the reverse direction of rotation. The solution to this case is to move the wires of different phases.

In single-phase motors, the main reason is the reverse direction of rotation. The solution to this is to check the header and change it from the guide.

3- Why does the engine overheat?

This case may be due to overload, which should be identified and if possible, the load on the motor should be reduced. Of course, this is if the incoming load is greater than the nominal load.

Low supply voltage affects the thermal performance of the electric motor. Therefore, checking the supply voltage value is a good solution for this case.

Engine cooling is done through the back fan and the holes of the cooling fan cover. Therefore, taking these holes increases the temperature of the engine. In this case, clean the holes of the cooling fan cover.

If the ambient temperature is high, the engine performance will be affected. To solve the problem in high-temperature environments and engine heating, the load on the engine should be reduced.

In three-phase motors, disconnection of one of the phases leads to a two-phase motor and its temperature increase. In this case, check all the wires and ensure their correct connection. This error can also be caused by grounding one of the coils, in which case the motor must be rewound.

The bale balance of winding current in three-phase motors is one of the reasons for the increase in the temperature of the electric motor. In this case, the sameness of the motor winding and the supply voltage should be checked.

This error can be caused by mechanical parts, especially bearings. In this case, the bearing should be checked and replaced if damaged.

4- What is the reason for the sound of the engine?

If the sounds from the engine are created momentarily and only when the engine is started, these sounds are considered normal and no special action is needed.

Disturbances and defects in the electrical insulation of the winding and connecting its coils will cause a lot of noise along with smoke. In this case, the power supply should be cut off quickly and the problem should be solved. However, if the winding is burnt, the item must be rewound by authorized repairmen.

The looseness of the coupling connecting the motor to the load can cause noise and vibration in the electromotor. In this case, the position of the coupling and its screws should be checked.

Sound and noise in electric motors can be caused by the looseness of mechanical holding parts, including screws, washers, holding plates, etc. These items should be carefully checked and tightened if they are loose.

Another cause of noise in the engine is the non-uniformity of the air gap between the stator and the rotor. In this case, check the caps and bearings.

5- Why are bearings and caps too hot?

This can be caused by a bent shaft or by correcting a weak shaft. In this case, it is necessary to replace the shaft.

If the load on the bearing is high, its temperature will also increase. In this case, it is necessary to check the alignment of the electric motor at the installation site, and the side and end force.

The breaking of balls or bearings can also cause the bearing to heat up. In case of encountering this current, it is necessary to change the bearing.

When using the drive in electric motors, a current flows in the shaft and bearing, which causes the bearing to heat up. In these cases, using insulated bearings is a good solution.

Since the motor may be connected to the load by belts and pulleys, excessive tension of the belt or improper size of pulleys can cause increased bearing damage. Re-adjusting the belt tension and using a suitable-sized pulley is a good solution for this problem.

The type and amount of grease have a great effect on reducing the friction of the bearing balls. Therefore, to prevent the increase of temperature and the destruction of the bearing, maintain the quality and the right amount of grease and make sure of the quality of the grease.

6- Why does vibration happen in electric motors and how can it be repaired?

In most cases, the cause of noise and vibration is the same. For example, problems in the winding, coupling, and mechanical parts are common factors in the production of noise and vibration. Therefore, the solution in these cases is similar to the solution that was mentioned in response to the problem of sound generation in the electric motor.

If one or more rods are broken or disconnected in squirrel cage induction motors, we will encounter vibration in the motor. This case can be solved by careful examination by an expert and then replacing the rotor.

The imbalance of the cooling fan and the breakage of its blades will cause the engine to vibrate. Replacing the cooling fan is a simple solution to this problem.

Another reason for engine vibration is improper installation or the installation structure not being strong. In these cases, checking and tightening the installation connections and also strengthening the installation structure are among the existing works.

7- What is the reason for not starting the engine?

The presence of wrong connections, failure of the cable or wire, and burning of the power supply fuse can be the reason for the engine not starting. For this reason, you must check the connections and fuses.

Noise and vibration in electric motors can be caused by damage to mechanical parts. These items should be checked carefully and replaced if the parts are damaged.

The presence of a large load can cause the electric motor to remain under load and vibrate, so reducing the load is a good solution in this case.

In some cases, the engine is started, but it keeps turning off and on during operation. In this case, check for loose connections in the power supply line, fuses, and control.

8- What are the common causes of failure of capacitor single-phase electric motors?

In these engines, if the acceleration time of the engine is too long, the engine will burn. To avoid this, check that the motor power is not too small for the load. Also, record the acceleration time. If the acceleration time is more than 3 seconds, there may be a problem with the starter capacitor.

Frequent and excessive starting of the engine will damage it. If the engine is started more than twenty times per hour, you should consider the necessary considerations.

Factors such as not placing the motor terminal voltage in the standard range or voltage surge at the input can cause damage to the motor. In this case, checking the supply voltage and providing a protector will prevent possible damage.

Troubleshooting in electro pumps:

1- What is the reason for not starting the pump?

The presence of wrong connections, wire failure, burnt power supply fuse, and cable disconnection can be the reason for not starting the pump. For this reason, it is essential to check all connections.

Jamming of the shaft, impeller, or bearing is one of the reasons why domestic water pumps do not start. To check this issue, the pump must be disassembled and the necessary measures for repair or replacement must be taken.

The burning of the stator winding or the capacitor has a significant effect on the failure of the pump to start. In this case, the coil and capacitor should be replaced.

2- Why does the pump work but there is no water suction?

This can be caused by the lack of water in the pump chamber. In this case, fill the inlet pipe and the pump chamber with water.

The water level is lower than the suction valve or the inlet valve can be the reason for the lack of water suction. In this case, adjust the installation height of the pump.

If there is air in the suction pipe, water suction in the pump will be disturbed. In this case, it is necessary to check the sealing of the inlet and outlet pipes.

Damage to the mechanical seal and the impeller of the water spreader is another reason for the mentioned error. In these cases, replacing the defective part will solve the pump problem.

Another reason for the lack of water suction is the wrong direction of the motor rotation. To solve this problem in three-phase motors, replace the two-phase connections, and in single-phase motors, check the header and change it according to the existing guide.

If the inlet filter is blocked by deposits or the water freezes in the chamber or pipes, the suction may not be done properly. To solve this problem, clean the inlet valve by removing deposits. Also, if the water freezes, start the pump after the ice melts.

3- Why does the thermal switch stop the pump?

Motor overload due to excessive friction and as a result of high current and heat generated causes the operation of the thermal switch. In this case, open the engine and take the necessary measures to prevent the suction of foreign materials and reduce.

4- What is the reason for insufficient output pressure in the pump?

Clogging of piping and inlet filter or pump housing with foreign materials can reduce the output pressure of the pump. In this case, cleaning the plumbing, one-way valve or pump housing will help to solve the problem.

The long length of the internal piping route and the presence of many bends in the building are some of the reasons for the insufficient output pressure in the pumps. For this case, a pump with a higher flow should be used, and if this problem is not solved, the piping route, the number of bends, and connections should be reduced as much as possible.

Choosing a pump with inappropriate power, head and flow can lead to insufficient output pressure in the pump. In this case, you should choose the right pump according to different parameters

If the diameter of the pipe is not chosen correctly, the pump will not have the right pressure. To solve this problem, the diameter of the pipe should be carefully selected according to the requirements and the diameter of the inlet and outlet of the pump.