Three warning signals before "oil spraying" of 35kV transformer bushing

2025-09-23 14:00:02

Here are three warning signals that require special vigilance from the duty officer. In order to help you quickly establish awareness, I have compiled a table to summarize their core information:

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 Understand the reasons behind the warning

The insulation oil and insulation paper inside the transformer bushing constitute the main insulation system. Once the casing is not tightly sealed (such as aging rubber pads or improper assembly), it may lead to:

Insulation oil leakage: causing a decrease in internal oil level and a decrease in insulation and heat dissipation capabilities.

Moisture intrusion: Moisture intrusion will reduce the performance of insulation paper, resulting in increased dielectric loss, increased partial discharge, and increased heat generation.

The accumulation of heat will accelerate insulation aging, generate more gas, form a vicious cycle, and ultimately may cause internal faults or even fuel injection.

 Daily inspection and precautions

In daily inspections, the duty officer should not only pay attention to the above three warning signals, but also do the following:

1. Standardized inspection:

Regularly (such as monthly) use an infrared thermal imager to conduct general testing on the casing and keep records for longitudinal comparison.

Observe whether the oil level and appearance of the casing are normal, and whether there are any signs of oil leakage.

Listen to the sound of the casing running in a quiet environment to see if there are any abnormalities.

2. Emphasize testing and oil supervision:

Strictly follow the pre testing procedures to conduct tests on the dielectric loss factor (tan δ) and capacitance of the casing, and pay attention to their changing trends.

Regularly perform chromatographic analysis on the insulation oil of the casing, paying attention to whether the content of characteristic gases such as hydrogen (H ?), acetylene (C ? H ?), and total hydrocarbons has increased abnormally.

3. Safe operation:

Maintain a safe distance during inspection and strictly prohibit touching the high-voltage parts of the equipment.

Report any abnormalities immediately and handle them according to the scheduling instructions. Do not operate blindly.

  Principles for handling emergency situations

Once any of the above warning signals are detected, or even fuel injection occurs, please immediately perform the following steps:

1. Immediate reporting: Report the on-site situation to the dispatch and superior supervisory department as soon as possible, including equipment numbers, abnormal phenomena, preliminary judgments, etc.

2. Strengthen monitoring: On the premise of ensuring safety, isolate abnormal equipment and strengthen remote monitoring (such as video surveillance or online monitoring devices).

3. Apply for power outage: Apply to shut down the faulty transformer as soon as possible for detailed inspection and testing to identify the cause of the fault.

4. Professional handling: Wait for professional maintenance personnel to arrive and handle. Do not operate or attempt to repair on your own to prevent the accident from escalating.

 Simple mnemonics help with memory retention

For the convenience of memory, please remember this mnemonic:

>Be alert when the oil level is low, and don't underestimate abnormal temperature.

>Abnormal noise discharge is an alarm, report it immediately and do not consume it.

Finally, please remember that behind every "fuel injection" accident, there are almost always a series of overlooked warning signals. Your meticulous observation, accurate judgment, and prompt reporting are the most critical factors in preventing accidents from happening.