The Forensic expert kollegium conducts measurements of electrical insulation resistance of cable lines, electrical wiring, and electrical equipment for the purpose of identifying insulation defects.

The quality of insulation determines the reliability and operability of the power system as a whole, as well as the safety of its use for personnel. Timely detection of insulation integrity violations helps prevent:

• premature equipment failure;
• short circuits in wires that may lead to fire;
• electric shock to operating personnel;
• various emergency situations.

Therefore, according to the rules for operation of electrical equipment, it is necessary to carry out measurements of electrical resistance, which provide information about the quality of insulation, its suitability for operation, and safety.

The value of electrical insulation resistance is regulated by many technical normative legal acts: technical codes of established practice, standards, electrical installation regulations (PUE), technical specifications, etc.

Measurements of electrical insulation resistance are carried out using a special device - a megohmmeter, which generates a specified test voltage. Using these measurements, it is also possible to determine the absorption coefficient (Kabs) and the polarization coefficient (Kpol).

The absorption coefficient is the ratio of the measured insulation resistance 60 seconds after application of the megohmmeter voltage (R₆₀) to the measured insulation resistance after 15 seconds (R₁₅). This coefficient determines insulation moisture content; if it does not comply with specified standards, the product is subject to drying.

The polarization coefficient indicates the ability of charged particles to move within a dielectric under the influence of an electric field, which determines the degree of insulation aging. The measurement method is based on comparison of megohmmeter readings taken 600 (R₆₀₀) and 60 (R₆₀) seconds after the start of testing.

These coefficients reflect the actual condition of the insulation and make it possible to draw conclusions about the causes of deterioration in insulation quality, which may include:

• mechanical destruction;
• exceeding the permissible load of insulated conductors, resulting in insulation integrity violations;
• aging (wear) of insulation;
• increased insulation moisture.

Based on the measurement results, it is also determined whether the equipment is suitable for use as a whole or whether special measures are required to eliminate insulation defects.

Measurements at the Forensic expert kollegium are carried out using equipment included in the State register of measuring instruments of the Republic of Belarus and properly verified in accredited laboratories of the State Standardization Committee of the Republic of Belarus.

Measurements of electrical insulation resistance at the Forensic expert kollegium are performed by qualified specialists who have undergone special training and possess the appropriate electrical safety clearance group.

You may contact the Forensic expert kollegium for consultation regarding measurement of electrical insulation resistance at: Minsk, Zhukovskaga St., 11A, 4th floor

or by phone: +375 (17) 317 04 71; +375 (17) 317 04 72; +375 (17) 317 04 73; +375 (17) 317 04 74; +375 (17) 317 04 76; +375 (29) 109 60 11; +375 (44) 588 60 11.