Preventive testing of electrical equipment

The primary issue for the safe operation of power equipment is ensuring the safety of the equipment and the reliability of relay protection. This applies not only to power equipment already in operation, but also to newly built power equipment. Although acceptance tests have been conducted upon delivery, preventative power testing is still essential.

Whether power equipment that has been in use for many years can continue to be put into operation should be decided based on the scientific conclusions provided by pre-testing. The technical performance of power equipment gradually decreases over long periods of operation, and its insulation and mechanical properties deteriorate due to environmental factors such as temperature, humidity, and dust during intermittent operation or long-term shutdown. Only through preventative testing can the safe operation of this equipment be determined. Preventative testing allows for timely understanding of the equipment's condition, and based on the analysis of pre-test data, equipment can be prioritized for orderly updates and repairs, thus ensuring safe operation.

Preventive testing of power equipment refers to the inspection, testing, or monitoring of equipment already in operation according to prescribed testing conditions (such as prescribed testing equipment, environmental conditions, testing methods, and testing voltage), testing items, and testing cycles. It is an important measure to determine whether equipment can continue to be put into operation, prevent accidents and equipment damage, and ensure the safe operation of equipment.

The most common preventive tests for power equipment include: AC withstand voltage test, DC withstand voltage test, partial discharge measurement, gas chromatography analysis, no-load current measurement, polarization index, absorption ratio, polarity check, and dielectric loss factor tan 8 test.

The results of preventive tests on power equipment should be compared with the results of previous tests on the equipment, with the results of tests on similar equipment, and relevant test results should be referenced. A comprehensive analysis should be conducted based on the patterns and trends of change before a judgment is made.