Phase failure is one of the most common causes of failure of three-phase motors. The machine continues to operate on two phases, but in emergency mode, which quickly leads to burnout of the winding. Let's look at the signs and protection.
Signs of phase failure
- The engine hums, but pulls weakly or does not start.
- Overheating of the housing even with a light load.
- Reduced speed and power.
- Increased noise and vibration.
- When starting without load, it does not move, only buzzes.
What is dangerous
When one phase breaks, the current in the remaining two increases sharply. The winding overheats, the insulation is destroyed, and within a few minutes to hours the motor burns out. The result is an expensive rewinding of the winding.
Causes of break
| Where | Cause |
|---|---|
| Power supply | Blown fuse, break wires |
| Terminal box | Loose contact, oxidation |
| Starter | Burned contacts |
| Winding | Internal break |
How to protect yourself
The best protection is installing a control relay phases or a modern thermal relay with protection against phase loss. It turns off the motor when a phase disappears, saving the winding. Read more about protection in the material about accident prevention.
Do you suspect a phase failure or has the motor already burned out? Elektromotors engineers in Tashkent will repair the car and select protection against a repeat accident - contact us.