Electrical equipment in Guizhou has been widely used in production, and electrical fault is inevitable, how to check the electrical fault is a big problem. Electrical maintenance personnel are the main technical force to face and solve this outstanding problem. It is the obligation and responsibility of every maintenance personnel to find out the fault accurately in the actual production and application, so as to eliminate the fault and make the electrical equipment operate normally and stably.

For some electrical faults, the abnormal temperature rise, vibration, smell, noise and color change of the faulty equipment can be directly sensed by touching, seeing, smelling and listening through the human hand, eye, nose, ear and other organs, so as to determine the fault location of the equipment.

1. Judgment of abnormal sound of power transformer

Normal operation of the transformer, clear and uniform buzz. If the sound of distribution transformer is abnormal, judge the cause of fault point. High hum, high pitch, overload or overvoltage.

Intermittent violent cluck sound, single-phase load increases sharply. With the sound of hammering, the core screw has been loosened. Clapping and clapping, the iron core ground wire is broken.

Intermittent wheezing, poor iron grounding. The short circuit of winding is slight, and there are bursts of crackling sound. The short circuit of winding is serious, which makes a huge noise.

There are cracks in the high-voltage bushing, which makes a high-frequency hissing sound. The high voltage lead shell flashed and crackled. The low-voltage phase line is grounded, and a roar is heard far away.

Drop switch tap, poor contact, squeak.

2. Detection of partial discharge of electrical equipment with semiconductor radio

It is difficult to find partial discharge during inspection of power transformation and distribution equipment. Carry pocket radio and adjust to no station. Turn up the volume and listen to the sound. The hum is normal.

If the sound is irregular, there is a very loud whiplash or squeak, and there is a partial discharge nearby. Then turn down the volume and measure it one by one near the equipment.

The sound of firecrackers was heard again, and the equipment was faulty. The equipment was partially discharged and emitted high-frequency electromagnetic waves.

3. Diagnosis of common faults of motor by using listening stick

Use the listening stick to listen to confirm the motor fault. The rotor rubs against the stator when a continuous chirp is heard. The rotation speed slows down, and the coil contacts the shell to ground.

The rotating speed becomes slow, the coil is broken and one phase is missing. The bearing chamber hissed and hissed, and the bearing lubricating oil dried up. It is concluded that the bearing has been damaged by the clucking sound of the bearing.

4. Knock method for checking hollow of wooden pole

Patrol and inspect the wooden electric pole, and hammer around the pole body. When the sound is clear and crisp, the body is hollow.

5. Inspection of bearing insulation condition of generator set by stripping insulated conductor

When the generator set is running, the bearing insulation should be inspected skillfully. One end of the wire should be grounded first, and the other end should touch the rotating shaft. Touch it carefully for many times.

Guizhou electrical equipment points out that if the electrical fault cannot be determined by human direct perception, various instruments and meters are needed to measure the voltage, current, power, frequency, impedance, insulation value, temperature, amplitude and speed of the fault equipment to determine the fault location.