Maintenance of instrument transformers requires periodic checks of insulation performance, connection integrity, and operating temperatures to prevent measurement errors or safety incidents caused by aging or malfunctions. For oil-immersed transformers, the oil level and quality must also be inspected to prevent the degradation of insulation properties. Selection, installation, and maintenance must be performed by qualified personnel to ensure the stable operation of the power system.
Visual Inspection: Check porcelain bushings and insulators for cleanliness, damage, cracks, discharge marks, or oil stains; for dry-type transformers, focus on checking the epoxy resin for cracking.
Oil Level and Color Inspection: For oil-immersed transformers, verify that the oil level is normal, the oil is clear (not black), and there are no signs of leakage; replace the desiccant in the breather if more than half of it has changed color.
Sound Inspection: There should be no abnormal sounds during normal operation; hearing "crackling" discharge sounds or "hissing" static discharge sounds indicates potential discharge or insulation issues.