Main Purpose and Common Methods of Insulation Resistance Test

Date：2023-03-20 09:00:00Views：862

Electrical equipment usually uses non-conductive insulating fiber products, mica, insulating oil, asphalt, glass, ceramics, polymer materials, etc. as insulating materials. The basic principle of insulation resistance meter testing is to apply a test voltage between the independent circuits under test and detect the leakage current of the circuit to obtain the insulation resistance value. This article has collected and collated some materials, hoping to have greater reference value for readers.

1、 Purpose of insulation resistance test

The insulation problem of electrical equipment in the power industry is the main factor causing electrical equipment failures, and the insulation performance also has a certain impact on the life of electrical equipment. Therefore, insulation testing is an important work in the inspection of electrical equipment. Insulation resistance is an important indicator for judging insulation performance. For any kind of electrical equipment, ensuring that its insulation resistance between phases and to ground is sufficiently high is one of the important indicators for the safe operation of electrical equipment. Therefore, measuring the insulation resistance of electrical equipment is a very important process.

2、 Test method for insulation resistance

When measuring the insulation resistance of equipment, the power supply must be disconnected first; For equipment with capacitive properties (such as cable lines), it is necessary to discharge them first and confirm that there is no electricity before testing.

The lead wire of the insulation resistance meter should be multi-stranded soft copper wire with good insulation performance. The two wires should not be intertwined to avoid causing measurement errors.

The insulation resistance meter should be placed in a horizontal position. Before connecting wires, first rotate the insulation energy meter to see if the pointer is at "∞". Short circuit the two terminals (L) and (E), and slowly rotate the insulation resistance tester to see if the pointer points to the "zero" position.

D. When measuring motors, large capacity transformers, cables, and capacitors, there should be a certain amount of charging time. The larger the capacitance, the longer the charging time. Generally, the reading of the insulation resistance meter after one minute of rotation shall prevail.

The surface of the object to be measured must be wiped clean and free of dirt to avoid electric leakage that may affect the accuracy of the measurement.

To ensure the reliability of the measurement results, it is necessary to repeat the measurement more than twice.

3、 Benefits of insulation resistance testing for electrical equipment

The insulation resistance of electrical equipment can be regarded as an important indicator for comprehensive analysis of the insulation performance of electrical equipment. Mastering the insulation performance of electrical equipment is conducive to the smooth completion of electrical equipment inspection work, and is also helpful for the maintenance of electrical equipment. At the same time, it can also achieve the normal and safe operation of electrical equipment. In addition to using a universal insulation resistance tester to detect the insulation resistance of various electrical equipment, zero value detection can also be performed on insulators on overhead lines using an insulator zero value detector or a wireless insulator distribution voltage tester to determine whether the resistance state of the insulators affects the safe operation of the overhead line.

The above is the relevant content of "Main Purpose and Common Methods of Insulation Resistance Test" brought by this core breaking test. I hope it can be helpful to everyone. We will bring more exciting content in the future. The company's testing services cover a variety of testing projects, including electronic component testing and verification, IC authenticity identification, product design and material selection, failure analysis, functional testing, factory incoming material inspection, and tape weaving. Welcome to call Chuangxin Testing, and we will wholeheartedly serve you.