How long after installation should a current transformer be tested?

After a current transformer is newly commissioned, it should undergo commissioning tests, including infrared precision testing, within one week (but more than 24 hours).

This typically applies to newly installed or overhauled equipment to ensure it is in good condition before formal operation. While "within one week" refers to the period for infrared precision testing, comprehensive commissioning tests (such as insulation resistance, turns ratio, polarity, withstand voltage, etc.) should generally be completed after installation and before formal energization. In other words, testing is not done after a period of operation, but rather all necessary checks and tests must be completed before commissioning to ensure system safety.

For certain specific tests, such as infrared precision temperature measurement, these are conducted within one week after the equipment has been energized for more than 24 hours, to detect potential heating defects.