Causes and Solutions for Motor Burnout in Powder Forming Hydraulic Press Hydraulic System
**Causes and Solutions for Motor Burnout in Powder Forming Hydraulic Press Hydraulic System:**
**I. Motor Burnout Due to Prolonged Overload or Overheating:**
- Cause: Accelerated aging of winding insulation due to long-term overload or overheating, leading to carbonization at weak points and causing inter-turn short circuits, phase-to-phase short circuits, or ground short circuits, resulting in local burnout of the winding.
- Solution:
1. Avoid prolonged overload operation of the motor.
2. Ensure the cleanliness of the motor and good ventilation for efficient heat dissipation.
3. Minimize frequent starts of the motor, and conduct dynamic balancing tests on the rotor of the hydraulic system motor when necessary.
**II. Motor Operation with Missing Phases:**
- Symptoms: Loud noise and severe heating of the motor in the hydraulic system of the multifunctional hydraulic press. Typically, the motor burns out within a few minutes of operation. Complete loss of a phase in the entire power supply system can potentially damage multiple motors in the hydraulic system.
- Cause: Burnout or charring of one or two phases due to factors such as blown fuses, faulty electromagnetic contactors, broken power lines, or poor connections.
- Solution: Various methods and devices can be used for phase loss protection, including thermal relays with phase loss protection, reverse current relays for phase loss protection, zero-sequence voltage relays for phase loss protection, broken wire voltage relays for phase loss protection, and protection using saturation current transformers.
**III. Winding Insulation Damage Due to Mechanical Vibration:**
- Cause: Mechanical vibrations, such as high current impact during startup and rotor imbalance in the multifunctional hydraulic press hydraulic system motor, lead to undesirable effects like turn-to-turn loosening and insulation cracks in the winding.
- Solution:
1. Minimize frequent starts, especially in powder forming hydraulic press hydraulic system motors.
2. Ensure that the vibration values of the driven equipment and the hydraulic system motor are within specified limits.
**IV. Poor Seal of the Motor Itself Leading to Insulation Erosion:**
- Cause: Inadequate sealing of the motor in the hydraulic system of the hydraulic press, resulting in immersion and erosion of the insulation, causing local burnout of the motor winding.
- Solution:
1. Eliminate equipment leaks as much as possible.
2. Pay attention to the seals at every part of the motor during maintenance. For example, apply a small amount of 704 sealant on various flanges, grease on bolts, and install splash-proof boxes, if necessary, at junction boxes where splashing may occur.
**V. Bearing Damage and Shaft Deflection:**
- Cause: Bearing damage, shaft bending, or other factors causing friction between the stator and rotor (commonly known as "rubbing"), leading to a rapid rise in the core temperature, burning insulation slots, inter-turn insulation, and eventually causing short circuits.
- Solution:
1. Heat the bearings to 80°C~100°C before disassembling them using methods such as bearing heaters or transformer oil baths.
2. Thoroughly clean the bearings before installation, ensuring no impurities are left in the bearing cavity, and maintain cleanliness when adding grease.
3. Avoid unnecessary shaft machining and nesting work of the hydraulic system motor in the hydraulic press.
4. Ensure proper alignment of the stator and rotor cores during the assembly of the hydraulic system motor.
5. Keep the motor housing clean, ensure proper ventilation, and maintain the cooling device without deposits. Prohibit the mixing of different lubricants.
6. Conduct a comprehensive integrity check of the bearings before installation.
7. For hydraulic system motors not in use for an extended period, conduct necessary disassembly checks and update bearing grease before use.