How to check the running cable?

2023-05-24 158

The new factory cable, also check the cable's various certificates, test reports, as well as the manufacturer's qualification report and cable appearance. But how to check the running cable, in fact, the cable inspection in operation is not complicated, generally these are the inspection items (taking the 10KV cable of Dodd Cable as an example):

First, the cable operating temperature

Use tools: infrared thermometer or thermal imager.

Operating standards: 3KV operating temperature does not exceed 75 ° C; 10KV generally does not exceed 35 ° C.

Second, the insulation resistance

Insulation resistance is one of the important indicators to measure the quality of a cable. Generally, the new equipment must be tested for the insulation resistance of the cable. The equipment should be shut down for more than 7 days and the insulation resistance of the cable and equipment should be measured.

Tools: Insulation resistance meter (shake table)

Measurement standard: For the low-voltage system, the resistance of the general cable is not less than 0.5MΩ; for the high-voltage cable, it is not less than 1MΩ per kilovolt; the small bus of the secondary circuit is not less than 10MΩ.

Third, measure the withstand voltage

The withstand voltage is generally required to do a withstand voltage test after the cable is newly put into operation or the cable is faulty and repaired to check the quality of the cable.

Measuring tool: AC withstand voltage generator or DC withstand voltage generator

Measurement mark: 10KV cable AC withstand voltage standard value is 35KV; 10KV DC withstand voltage standard value is 40KV.

Fourth, the absorption ratio K = R "60 / R" 15

The absorption ratio is an indicator of the moisture content of the cable.

Measuring tool: insulation resistance meter

Measurement standard: K ≥ 1.3

The above data is based on the 10KV cable of Dodd Cable. The different types of cable testing methods are different. For details, please consult the staff of Dodd Industrial.