Why does a water pump burn the motor? Starting with a load can cause damage to the motor; the actual head used is too much lower than the pump nameplate head; some special pumps work without water for too long; ...... etc., many situations can cause burned motors. The following Ace lobe pump 's will take you through the analysis.
A. Motor burning bearings (mechanical failure) or burning coils (electrical failure)
Burning of the coil is mainly caused by over-current, sometimes the voltage is too high or too low can also cause the coil to heat up and short circuit, so first check if the voltage during operation is too different from the rated voltage.
In general, the causes of overcurrent short circuits are the following.
1, equipment overload operation, so that the motor for a long time in the rated current or over rated current operation. Special attention should be paid to the fact that the starting current of the motor is 3-5 times the rated current, so you should try to avoid starting the equipment with a load or running at full load (mainly depending on the rated current of the motor and the matching margin of the normal running current)
2, the motor works in a more humid working environment. Before starting the motor should check the insulation of the coil to ground and phase insulation, different use voltage levels insulation requirements are different, you can refer to the relevant national standards to check. During the operation of the motor, attention should be paid to the waterproofing and moisture-proofing of the motor.
3, mechanical failure of the pump machine caused by motor overload, excessive current and burned coils.
4, the motor's heat dissipation out of the problem. General motor coils are air-cooled shell, submersible pumps are water-cooled shell. Large motors mostly use air-air heat exchanger, air-water heat exchanger cooling. If the cooling water (air) is broken, so that the coil can not dissipate heat, are likely to burn the coil.
Second, the actual use of head is too much lower than the pump nameplate head
Pump head is used to overcome the height and resistance, high head pump in the high head point of work when his flow is the design point of the flow, if the work at low head, equivalent to the pump outlet resistance is reduced, this time the pump flow will increase, the motor will be overloaded, super to a certain extent will burn the motor.
Third, the pump works too long without water
If the water-cooled submersible motor, in the absence of water, the motor can not pass through the water, cooling the motor, resulting in the motor temperature rises, the coil if there is no overheating protection device, within a few seconds to 1 minute, the motor can burn the machine, so the injection of water is not enough is the main reason for the rapid burning of the motor!
Fourth, starting with a load can cause damage to the motor
When starting a three-phase motor, the starting current is very high, which can reach 4~7 times of the rated current. The large starting current will cause a large voltage drop on the line in a short time, which will not only affect the starting of the motor itself but also the normal work of other motors and electrical equipment on the same line.
Five, the lack of phase is another major cause of motor burnout
Whether ordinary motor or submersible motor is out of phase burn motor accounted for 60%-80% of the proportion, followed by bearing damage due to burn motor accounted for 20%.