What are the causes and solutions for hydraulic system motor burnout

Electric motors are essential components in hydraulic systems, and many motors often operate at overload in hydraulic stations. Therefore, there are incidents of motor burnout during operation. Motor burnout can cause all hydraulic systems to malfunction, seriously affecting production safety. What are the factors and solutions for hydraulic system motor burnout?

1、 Due to prolonged overload or overheating operation, the aging of winding insulation accelerates, and the carbonization of the thinnest insulation defect leads to inter turn short circuits, inter phase short circuits, or ground short circuits, causing some damage to the winding.

Solution:

① Try to avoid overloading the motor during operation.

② Ensure that the motor is clean and has excellent ventilation and heat dissipation.

③ To avoid repeated starting of the motor, it is necessary to conduct dynamic balance tests on the motor rotor if necessary.

2、 Lack of phase work

At this time, the noise of the motor is very loud and it generates severe heat, which is also the fatal killer of three-phase asynchronous motors. Generally, it burns out after working for more than ten minutes. If all power supply systems are out of phase, it is very likely to cause damage to multiple motors. Lack of phase is often caused by the burning phenomenon of one or two phases. Single phase operation is caused by an open circuit in one phase of the motor power supply. The elements that make up the open circuit are often blown fuses, poor electromagnetic contactors, disconnected power lines, or poor wiring.

Solution:

There are many methods and equipment for motor phase failure protection. After searching online, Xuli Hydraulic introduces the following common protection methods: using thermal relays with phase failure protection equipment for phase loss protection; Reverse current relay phase failure protection; Zero sequence voltage relay phase failure protection; Broken wire voltage relay phase protection; Use speed saturation current transformers for protection, etc.

3、 The insulation of the motor winding is affected by mechanical vibration, resulting in phenomena such as inter turn looseness and insulation cracks. The damage effect continues to accumulate, and thermal expansion and contraction cause friction on the winding, accelerating insulation aging. After all, the earliest carbonized insulation is damaged until the winding is burned.

Solution:

① Try to avoid initiating repeatedly, especially for high-voltage motors.

② Ensure that the vibration values of the dragged equipment and motor are within the specified range.

4 The poor sealing of the motor itself causes the insulation of the motor coil to be corroded, and the most severe part or the thinnest insulation defect occurs at a point to ground, resulting in phase to phase or turn to turn short circuits, which then causes some damage to the motor coil

Motor burned out. Motor burned out

Solution:

① Try to eliminate the dripping phenomenon of equipment as much as possible

② When repairing, pay attention to the sealing of every part of the motor, such as applying a small amount of 704 sealant to each flange, applying grease to bolts, and if necessary, installing splash proof boxes in junction boxes and other places. If the motor leaks and is prone to liquid and dirt invasion, a protective cover should be installed;

③ Motors working in this environment should have their minor and medium repair cycles shortened, and in severe cases, medium repairs should be carried out promptly.

Five Due to factors such as bearing damage and shaft bending, the friction between the stator and rotor causes a sharp rise in the temperature of the iron core, burning out the insulation of the slot and the insulation between turns, resulting in a winding turn short circuit or "firing" to ground. In severe cases, it can cause the stator core to be reversed, misaligned, the shaft to wear out, and the end cap to become invalid.

Solution:

① When disassembling bearings, it is generally necessary to heat the bearings to 80 ℃~100 ℃, such as using bearing heaters, transformer oil boiling, etc. Only in this way can the equipment quality of the bearings be guaranteed.

② It is necessary to carefully clean the equipment bearings before use. There should be no impurities left in the bearing chamber, and it is necessary to ensure cleanliness when filling with grease.

③ Try to avoid unnecessary shaft machining and motor end cover nesting work.

④ When assembling the motor, it is necessary to ensure that the stator and rotor iron cores are aligned and not misaligned.

⑤ The cleanliness of the motor casing is essential, and ventilation must be ensured. The cooling equipment must not have any scale buildup, and the fan blades must remain intact.

⑥ Prevent the mixing of multiple lubricants.

⑦ Before installing the equipment bearings, it is necessary to conduct a thorough and defect free inspection of the bearings.

⑧ For motors that have not been used for a long time, it is necessary to conduct a necessary breakdown inspection and update the bearing grease before use.