Safety Risks Brought by Malfunctioning Transformer Oil Level Indicator

The malfunctions of transformer oil level indicators are mainly divided into mechanical failure, sealing failure, sensing failure and display failure, each with distinct fault characteristics and corresponding safety risk scenarios, which pose layered threats to transformer operation safety. Mechanical failure is the most common type, including float rod jamming, transmission gear stuck and pointer failure to reset. This type of fault is mostly caused by long-term dust accumulation, internal rust and mechanical aging. Its typical feature is that the oil level display remains static for a long time and cannot change with the actual oil level fluctuation. In actual operation, this fault will cause operation and maintenance personnel to fail to find the slow oil leakage of the transformer in time. Long-term oil shortage will lead to insufficient internal insulation protection, resulting in partial discharge and insulation breakdown of high-voltage components, and further triggering transformer short-circuit faults. Sealing failure is mainly derived from the aging and damage of waterproof and dustproof structure, which leads to water vapor and dust entering the inside of the indicator. The characteristic is blurred dial, internal condensation and sensitive component corrosion. This failure will not only aggravate the damage of the indicator itself, but also cause moisture to penetrate into the transformer oil tank along the connecting structure, reduce the insulation performance of insulating oil, accelerate the aging of insulating paper, and greatly shorten the service life of transformer internal insulation system. Sensing failure mostly occurs in intelligent electronic oil level indicators, including data drift, signal interruption and inaccurate induction. It is characterized by unstable oil level data display and large deviation from the actual value. In high-load operation scenarios, false high oil level data will make personnel misjudge the equipment state, ignore the hidden danger of oil level drop caused by high-temperature oil expansion and later cooling shrinkage, and finally lead to insufficient heat dissipation of the transformer, local overheating and component burnout. Display failure refers to complete screen blackout, pointer loss and other faults that cannot display data normally, resulting in complete loss of oil level monitoring function. In unattended outdoor substation and pole-mounted transformer scenarios, this fault will make the transformer in a blind monitoring state for a long time, and any oil level abnormality cannot be detected and handled in time, which is extremely easy to induce major power equipment accidents. In general, all types of oil level indicator malfunctions will break the safety monitoring balance of transformers, expand equipment operation risks, and bring hidden dangers to the stable operation of regional power grids.