How to deal with dry power transformer after wet?
Rainy or hot weather significantly increases the risk of moisture intrusion in dry-type power transformers. Moisture-affected transformers are highly susceptible to short circuits and other critical faults, which can lead to costly downtime and equipment damage. Prioritizing effective moisture treatment is essential to minimize failures and extend the transformer’s service life. Below are two reliable, industry-proven methods for drying damp dry-type power transformers.
Tank Winding Heating Method
This method involves using eddy current losses to dry the transformer, leveraging an external winding around the transformer tank.
- Setup: Place the entire transformer body inside an oil tank. Wrap an external power frequency coil around the tank wall—for easier winding, opt for fewer coil turns or lower current (a balance between practicality and heating efficiency).
- Technical Parameters: Use a 35–50mm² wire with a recommended current of 150A. First, pad multiple asbestos strips on the tank wall to insulate and protect the surface, then wrap the wire around these strips.
- Temperature Control: Strictly monitor temperatures during the process: the tank wall temperature must not exceed 115°C–120°C, and the transformer body temperature should stay within 90°C–95°C to avoid insulation damage.
Hot Air Drying Method
A straightforward and widely used approach, this method relies on controlled hot air to remove moisture without damaging components.
- Placement & Equipment: Position the transformer body outdoors in a well-ventilated area. Use a hot air generator, equipping its air inlet with a filter to block dust and sparks—preventing contamination or fire risks.
- Temperature & Airflow Rules: Gradually raise the inlet hot air temperature, ensuring it never exceeds 95°C (abrupt temperature spikes can harm insulation). Avoid directing hot air straight at the transformer body; instead, blow air from multiple directions to promote uniform drying.
- Moisture Evacuation: The circulating hot air will draw moisture out, which escapes through the transformer’s tank cover vents—ensure these vents are unobstructed throughout the process.
These practical solutions effectively resolve moisture-related issues in dry-type power transformers. If your transformer encounters other faults or you need tailored guidance for specific models, feel free to consult our technical team or reach out to our manufacturers for professional support.