35KV Fully Sealed Three-phase Oil-immersed Distribution Transformer

I.35kv Oil immersed Transformer overview

 Against the backdrop of global electricity demand growth, 35kV three-phase oil immersed transformers are widely used in rural power grids, industry, commerce, new energy, public facilities, and other fields. High reliability operational verification in over 50 countries and regions worldwide; Already sold to countries and regions such asRussia, Belarus, Ukraine, Uzbekistan, Kazakhstan, Tajikistan, Turkmenistan, Kyrgyzstan, Vietnam, North Korea

II.35kv Oil immersed Transformer Advantage

6. Overload capacity: Copper coil 35kv transformer allows short-term overload to 150% of rated capacity for no more than 2 hours, but requires monitoring of oil temperature (≤ 95 ℃).   

III.35kv Oil immersed Transformer Type

IV.35kv Oil immersed Transformer Technical Specifications

   - Input voltage: 35kV

  - Output voltage: 0.4kV
  - Capacity: 50-5000 kva
  - Frequency: 50HZ/60HZ
  - Voltage regulation mode: NLTC (no Load tap changer)
  - Remark: voltage, capacity, frequency, connection group and loss can be customized according to customer requirements

V.35kv Oil immersed Transformer Case show

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VI.35kv Oil immersed Transformer FAQ

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 What is an 35kV three-phase oil immersed transformer?

A three-phase oil immersed transformer is a power transformer that is cooled and insulated by insulating oil. It is designed for use in three-phase AC power systems and can convert high voltage electrical energy into low voltage (such as 35kV/400V). It is widely used in industrial, commercial, and power grid distribution.

 

What are the typical application scenarios for Q2?

*Voltage conversion of urban distribution network (35kV → 400V);

*Power distribution in industrial plants such as mines and petrochemicals;

*Grid connection of renewable energy power plants (such as wind farms);

*Hospitals, data centers, and other places that require high reliability power supply.

 

What is the rated capacity range of Q3?

The common capacity ranges from 25kVA to 10MVA, with the 100kVA to 2000kVA models of 35kV/400V being the most widely used, depending on the load requirements.

 

What is the difference in maintenance cycle between Q4 35kV dry-type and oil immersed transformers?

Dry type: Dust removal inspection every 2-3 years; Oil immersed: Check the oil level, oil quality (pressure resistance value, acidity), sealing, and radiator cleaning once a year; Comprehensive oil sample testing every 3-5 years (such as medium loss and moisture content).

 

How to choose between Q5 three-phase oil immersed transformer and dry-type transformer?

-35kV oil immersed transformers are suitable for outdoor, high-capacity, and high load scenarios, with low cost but requiring regular maintenance;

-35kV dry-type transformer: used in indoor environments with high fire protection requirements (such as shopping malls and subways), maintenance free but expensive.

 

How to determine whether a transformer needs to change oil or filter oil?

-Oil quality testing: Regularly test the breakdown voltage (should be ≥ 30kV), water content (≤ 20ppm), and acid value of the oil;

-Cloudy oil color: The oil becomes darker or there is an increase in suspended matter;

-Decreased insulation performance: determined by withstand voltage test.

 

 

What are the reasons for the abnormal temperature rise during Q7 operation?

-Long term overload;

-Cooling system malfunction (fan/oil pump shutdown);

-Oil circuit blockage or insufficient oil volume;

-Internal short circuit or poor contact.

 

How to deal with oil leakage in oil immersed transformers?

-Slight oil leakage: tighten bolts or replace gaskets;

-Serious oil leakage: Stop immediately, drain the oil and repair or replace components;

 

What protective devices must be configured for Q9?

*High voltage side: circuit breaker or fuse (with overcurrent/short-circuit protection);

*Body protection: gas relay, pressure relief valve, oil temperature gauge;

*System protection: lightning arrester (anti lightning impulse)

*Monitoring device: oil level gauge, online oil chromatography analyzer (high-end configuration).

 

 

What are the key points to pay attention to when installing Q10?

-Stable foundation, horizontal installation, avoiding tilting;

-Reserve sufficient heat dissipation space (such as at least 1.5 meters away from the wall);

-Grounding resistance ≤ 4 Ω;

-Check the oil level, sealing, and cleanliness of the casing.