10 MVA Transformer, The Ultimate Guide

Distribution transformers have classifications and categories based on their features, applications, and specifications. One of which is the 10 MVA transformer. Let’s talk about what it is, its purpose, benefits, and its kinds in this article. 

3 phase transformer over a single phase

Electricity is essential in the modern world. It powers our homes, businesses, and industries. Generally, power utilities use distribution transformers to step up or step down voltage levels, ensuring a reliable and uninterrupted flow of electricity at your residential properties.
DAELIM is the world’s top professional Transformer and electrical equipment manufacturer. This company has been a reliable and trusted brand for more than 15 years.

Pad-mounted Transformer

We can provide you single phase and three phase pad mounted transformer

Dry-type Transformer

Type:Cast resin; Rated Capacity: Up to 25MVA; Rated Voltage: Up to 36KV;

Pole Transformer

TypeCSP type Frequency: 50/60Hz; Rated Power: 5~167kva

Oil immersed transformer

Frequency: 50/60Hz Rated voltage:10kv, 20kv,30kv Rated Power: 400~2500kva

Table of Contents

What Is a 10MVA Transformer?

10 MVA Transformer

A 10 MVA transformer is a type of distribution transformer that can help generate electricity supply to larger businesses and establishments outside of a residential property. Volt Amperes (VA) is the unit of measurement for the engineering’s amount of electrical load. 1 MVA is equivalent to 1,000,000 volt amperes. Subsequently, 10MVA is 10,000,000 volt-amperes. 


To ensure the quality of these distribution transformers, all manufacturers guarantee that they have gone through the following standard tests:

  • Insulation resistance
  • Withstand voltage testing
  • Amount of windings resistance
  • Inspection of vector group and voltage ratio
  • Impedance test
  • No-load test with a rated voltage and frequency
  • Oil leakage test
  • Withstand testing with induced over-voltage
  • Partial discharge measurement

10 MVA Transformer Specification

10 MVA Transformer Specification

The 10 MVA transformers’ specifications include their main application as power transformers. Because they are used to supply power, they are mainly used in electric power distribution and generation, as well as helping reduce losses during the transmission of electrical power. Additionally, these transformers are preferred when the load needs to run 24/7 at full capacity. 

More importantly, these distribution or power transformers are the main supply stepping up or down certain voltage levels. Aside from their main application, an important specification is their transformer concept. 

Generally, 10 MVA transformers utilize oil-immersed conservator rigid tanks with cooling radiators, preventing overheating and sudden shutting down of the machine. 

The following are other essential specifications of this transformer:

  • Rated Power: 10,000 kVA
  • Cooling Method: ONAN
  • Frequency: 50 Hertz
  • Voltage Ratio: 33,000/11,000V
  • Voltage Regulation: contains a 16-step motorized OLTC with on-load tap changers
  • Oil and Wind Temperature Rise: 65K and 60K, respectively
  • Oil Weight: Approximately 7500 kg
  • Efficiency: Level II to III, 3 to 4 Star
  • Transport Weight: Approximately 16,500 kg
  • Total Weight: Roughly 28,000 kg 

Types of 10 MVA Transformer

These power transformers are mainly divided into two classifications: oil-cooled and three-phase:

Three-Phase Transformer

10 mva Three-Phase Transformer

Three-phase transformers are composed of three pairs of secondary and primary windings, with a total of six coils. Each pair are wrapped around a single leg of a specific iron core assembly. In the construction, all three sets of coils should be separated by an angular difference of 1200 for maximum efficiency during function. 

Additionally, three-phase transformers are constructed by winding three single-phase transformers around one core. They would need a single neutral wire and three conductors to allow one circuit completion. These power transformers are mainly for industrial and heavy-duty applications, with the following benefits:

  • The power supply needs less copper
  • It can still function efficiently on power loads with longer ranges
  • Guarantees a smooth and continuous power delivery
  • Improved conductor efficiency

Oil Cooled

On the other hand, oil-cooled types describe the cooling design of an MVA transformer. You must note that knowing the cooling design is essential because it helps you determine whether the transformer is maintained at the ideal temperature that allows proper maximum function. 

If the transformer is oil-cooled, the coils are allowed to be dipped in mineral oil. Doing this allows the transformer to function effectively and supply power because the internal temperature is maintained. In oil-cooled transformers, there is a dissipation of the mineral oil used through the radiators that are attached to the transformer’s tank. 

Additionally, you can enhance cooling by installing fans near the radiators, bringing the temperature of the transformer to the desired level. 

10 MVA Transformer Mining Power Supply

10 MVA Transformer Mining Power Supply

A bitcoin mining power system utilizes transformers as high as 10 MVA for generating efficient and maximum power for mining. 

This power transformer allows medium voltage conversion from a certain substation, giving the ideal power for mining. Generally, crypto mines use transformers with 1000 kVA to 5,000 kVA increments. 

The main purpose of bitcoin mining is to generate a network for transaction confirmations essential in the maintenance and development of blockchain ledgers. 

Ultimate Bitcoin Mining Power Supply Guide – Power Transformer

Why do you need to do a transformer oil analysis?

A transformer oil analysis mainly analyzes oil samples obtained from certain electrical equipment at certified laboratories. Generally, a laboratory can determine the oil’s voltage breakdown through this analysis and its physical and chemical properties. 

The following are the included results after transformer oil analysis:

  • Color
  • Dissolved gas analysis and metals
  • Dielectric breakdown voltage
  • Inhibitor content
  • Flashpoint
  • Interfacial tension
  • Furan
  • Moisture
  • Power factor
  • PCBs
  • Specific gravity

Through this oil analysis, you can also determine whether measures have to be undertaken to eradicate problems and prevent unfortunate situations. Transformer oil analyses are essential because they help maintain your transformer oil’s quality to prevent your machine from dismantling or damaging. 

You should remember that transformer oil can degrade because of heat, load, and contamination of gas or water. When the oil is not in its premium state, it can affect your transformer’s cooling and dielectric properties. 

Regularly performing an oil analysis allows you to do a  regular inspection of your transformer oil to address any oil deteriorating condition. Doing this helps extend the life of transformers because a transformer oil analysis can help prevent any sudden transformer shut down or explosion, affecting human life as well. 

Where are transformers usually placed?

transformers usually placed

Generally, you can see transformers in three different locations: overhead, underground, and directly buried. 


Overhead transformers are normally seen directly with electric wires on similar poles close to high-voltage source conductors. When the transformer is larger, it’s normally positioned on overhead platforms alongside buildings, in alleyways, or on top of ground-level pads with fencing protection. Overhead construction is cost-effective and affordable but is more susceptible to wind and ice storms. 


Another common method of storing transformers is underground together with the electrical cables. However, nowadays, it’s also common to position them on ground pad mounts with cables and wirings feeding from the underground. 

Directly Buried

Finally, there have also been attempts to place power transformers directly buried in the ground without proper ventilation. Many large establishments and electrical business companies prefer this method because the transformers are out of sight, preventing damage from lawnmowers, heavy trucks and automobiles, and windstorms. 

However, you must be aware of the major challenges when you choose to bury transformers directly:

  • The operational accessibility is limited
  • Risk of a corrosive environment because of the lack of ventilation
  • Difficulty in the transformer’s heat dissipation

What are the advantages of a 3 phase transformer over a single phase?

The following are the advantages of three-phase transformers over the single-phase ones:

  • More affordable and cost-effective
  • Smaller and lighter
  • Easier assembling and installing
  • Can deliver more power
  • Can fit in smaller spaces
  • Improved efficiency
  • Easy to transport, repair, and maintain

Three-Phase Transformer: The Ultimate FAQ Guide


10 MVA transformers are one of the most important machines each individual needs to function daily. These distribution transformers allow efficient and rapid power generation without causing any short-circuit or potential damage to your appliances and establishments. 
Daelim guarantees that you can obtain the best possible transformer for your power needs. We know that you value your transformer products, and we want to help you get the best products at an affordable price.

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