The manufacturer of the distribution box tells you how to test the insulation of electrical equipment

To put it bluntly, insulation is a safety and preventive measure that uses non-conductive chemicals to protect or encapsulate charged bodies to maintain electric shock accidents. For electrical equipment used for a long time, the insulation may be brittle and the terminal wire may be loose. According to the test insulation, it can ensure the safe operation of electrical equipment and routes and avoid personal safety accidents.

Proper way to detect insulation

1. Use a qualified megger with appropriate rated voltage, and check that the megger characteristics are intact (the wiring gently swipes the meter needle to mark the zero position).

2. Pay attention to the name and serial number of the tested equipment, check that the power switch on each side of the tested equipment is disconnected, and check that no one is working on the tested equipment and there is no barrier to closing.

3. Use a electroscope (or a stylus) with appropriate and qualified rated voltage to verify that the tested equipment does not have working voltage.

4. Connect the megger to the equipment to be tested, and the rotating speed ratio of the megger shall be steadily increased to about 120 rpm, maintain the index value of the megger stable, and load it for measurement 60 seconds later.

5. Record data information and analyze data.

common problem:

1. Two persons are required to use a megger to measure the insulation of high voltage equipment.

2. Insulated transmission lines shall be used for measurement, and their ends shall be provided with insulating sleeves.

3. When measuring insulation, be sure to disconnect the equipment to be tested from all levels, verify that there is no working voltage, and clearly verify that no one is working on the equipment before starting. During the measurement, no one is allowed to get close to the equipment. Before and after the insulation measurement, the measured equipment must be charged and discharged to the ground.

4. When measuring the insulation on the line with induced voltage, be sure to cut off the other circuit to carry out the measurement. When lightning strikes, it is prohibited to measure the insulation of the line.

5. When measuring the insulation resistor around the inductive electrification device, the measuring staff and the placement position of the megger must be selected appropriately and the spacing must be maintained to prevent the megger wire or wire support from touching the inductive electrification part. When moving the wire, be sure to pay attention to monitoring to avoid electric shock accidents.

6. The surrounding working temperature and ambient humidity shall be mastered before and after the measurement.

7. The megger shall be placed in a stable area to prevent strong vibration and rotation.

8. Do not shake the rocker fast or slow to prevent the needle from shaking too much and causing deviation.