Notice before self inspection: Non professional self inspection (high-voltage transformers require professional operation) is only used to preliminarily discover obvious abnormalities. During self inspection, avoid rainy or humid environments. All operations must be carried out in a power-off state or at a safe distance (at least 1 meter), and do not attempt to open the casing or touch internal components. Any uncertain situation should be prioritized for contacting professional power personnel to ensure personal safety!

1、 Appearance inspection (observation under power-off state or remote viewing)

Whether there is oil leakage (oil immersed transformer)

Check for oil stains on the fuel tank, valves, and welds, and ensure that the oil level is within the normal range.

Warning: Oil leakage may cause insulation degradation or fire

Integrity of appearance and components

Whether the shell is deformed, corroded, cracked or damaged, and whether there are discharge marks on the transformer from a distance after thunderstorms (such as damaged porcelain bottles and blackened shells).

Check if the components are clean, damaged, dirty or cracked, which may cause discharge. Use a dry cloth to clean them (operate after power off!)

Whether the connecting wires (cables, busbars) are loose or detached, and whether the insulation layer is aged or damaged (such as cracked outer skin or exposed metal wires)

2、 Operation status check (remote observation or listening)

Abnormal noise

Normal: The transformer may emit a uniform "buzzing" sound (electromagnetic vibration sound)

Abnormal: emitting "sizzling" or "crackling" sounds, sharp or explosive sounds, or abnormal vibration sounds

Overheating phenomenon (do not touch directly)

Approach the shell with the back of your hand at a safe distance and feel if there is any abnormal high temperature. If the nearby air is noticeably hot, it may be due to poor heat dissipation or internal overheating.

Dry type transformers can observe whether the insulation material changes color on the appearance (blackening=high temperature damage)

Odor

Burning smell, oil fume smell=insulation material damage, immediately stay away and report for repair!

Indicator lights and instruments (if any)

If the transformer is equipped with a control panel, observe whether the indicator lights are normal (such as the power light being constantly on and the fault light not being on), and whether the values of the instruments (voltmeter, ammeter) are within the nominal range (non professionals can record changes in values, and sudden large fluctuations are abnormal).

3、 Environmental inspection

Is the ventilation and heat dissipation good

There are no obstructions within 1 meter around, and the cooling fan (if any) is operating normally. If birds or small animals are found nesting on the transformer, contact the power department in a timely manner to prevent the risk of short circuit.

environmental safety

Confirm that there is no risk of water accumulation, cable dropping, or human damage around the transformer.

4、 What should I do if I find any abnormalities? Correct operating procedures for non professionals

1. Do not handle it on your own

If any dangerous situations such as electric charging, smoking, sparks, or severe abnormal noises are found in the shell, immediately evacuate to a safe area, call the power service hotline (such as State Grid 95598) or contact the property management or professional electrician to explain the specific phenomenon.

2. Record abnormal details

When reporting for repair, provide specific abnormalities in the location, appearance/sound/odor of the transformer, and the time of discovery to help professionals quickly determine.

3. Be alert to secondary dangers

If there is water accumulation or cable dropping around the transformer, there may be a risk of leakage. Use clear signs (such as warning signs and fences) to isolate the site and remind others to stay away.

Recommendation for self inspection frequency: Daily observation should be conducted at least once a week, regular inspections should be conducted once every quarter or every six months, and additional inspections should be conducted during special periods or abnormal weather. The higher the self inspection frequency, the better. The key is "sustainability" and "targeting", adjusting in a timely manner in combination with environmental changes to avoid formal inspections.