The Ultimate Guide to 5mva Transformers

There are many types of 5mva transformer on the market, including pad mounted transformers, dry-type transformers, oil-immersed transformers, single-phase and three-phase, etc., so what are their differences and applications? How do I choose and buy a 5mva transformer? Let's take a look.

Types of 5MVA transformer

1. According to the number of power supply phases, 5MVA transformers are divided into single-phase and three-phase transformers;

2. According to the purpose, 5MVA is divided into:

Step up Transformers: Transformers for Power Generation Sites

Step down transformer: in the main transmission grid and in the distribution system

The function is: to realize the conversion between different levels of voltage

3. According to the cooling method, 5MVA transformer is divided into a dry transformer and oil immersed transformer.

4. According to the electricity load is the 5MVA transformer divided into power transformers, special transformers (mine transformers, traffic transformers, electric furnace transformers) test transformers, and measuring transformers.

5. According to the number of windings, 5MVA transformer divided into: two-winding transformers, three-winding transformers, autotransformers

6. According to the material 5MVA transformer is divided into the copper transformer and aluminum transformer

7. For the installation of a 5MVA transformer, you have two options: pad mounted transformer and floor transformer.

5 MVA Pad-mounted transformers are installed on a concrete pad, typically outdoors or within utility enclosures. They provide a compact and secure solution, with easy accessibility for maintenance and servicing.

Floor transformers, on the other hand, are installed indoors, directly on the floor. They are commonly used in commercial and industrial settings, especially when space constraints or specific requirements call for indoor installation.

Choosing between a pad-mounted transformer and a floor transformer depends on factors such as available space, environmental considerations, and project specifications. Contact us to discuss your specific needs and find the best installation solution for your 5MVA transformer.

Get it now: How Much Do You Know For The Different Types Of Transformers?

What are the international standards for 5MVA transformer?

The international standards for the 5MVA transformer that we often encounter are IEEE standard C57; CSA C88, ANSI, AS, GOST, etc. The main market for Dalin transformers is in North America/South America/Australia. Therefore, Daelim's 5mva transformer fully complies with IEEE/ANSI/CSA and AS standards.

Learn More About IEEE C57 Standard

The Difference Between 5MVA Power Transformer And Distribution Transformer

Different uses

5 MVA transformers that step down the voltage to the working voltage of electrical equipment are called distribution transformers.

This kind of transformer is used for daily lighting and factory electricity, and the low voltage is generally 0.4kV and below.

5mva distribution transformer is used in the power distribution system. The power transformer is used for the transmission of high-voltage electrical energy in the main power transmission network and is a transformer at all levels used before power distribution.

Read more: 5000kVA 12kV Pad Mounted Transformer

Different sizes

Typically, power transformers are larger in size than their counterparts for distribution transformers.

Furthermore, the installation process of power transformers is very complex and challenging.

Therefore, compared to power transformers, 5MVA distribution transformers are smaller and lighter. The installation process is also simple. In particular, the 5MVA pad-mounted transformer has a compact structure and is easy to install and maintain, so it is widely welcomed by Bitcoin customers in North America.

Different voltage

The voltage level of 5MVA power transformer is relatively high, usually 35kV and above, while the voltage level of 5MVA distribution transformer is below 35kV.

How to choose a 5 MVA  transformer?

1. First, investigate the power supply voltage of the place where the electricity is used, the actual electricity load of the user, and the conditions of the place where it is located, and then select one by one according to the technical data indicated on the transformer nameplate;

2. Consider the primary voltage, secondary voltage, current and environmental conditions of the 5mva transformer.

3. During normal operation, the power load of the transformer should be about 75-90% of the rated capacity of the transformer. In operation, if it is measured that the actual load of the transformer is less than 50%, the small-capacity transformer should be replaced. If the rated capacity of the transformer is greater than 5MVA, the large transformer should be replaced immediately.

4. It is best to choose a low-voltage three-phase four-wire power supply. This can provide power and lighting power at the same time.

Try for free: How To Choose The Suitable 110KV Power Transformer?

What type of oil is used in the 5MVA transformer?

There are usually two kinds of oil used in transformers, one is mineral oil with high-cost performance; the other is the vegetable oil which is friendly to the environment. Either mineral oil or vegetable oil can be used in 5MVA transformers. Daelim Transformer can provide you with ul-certified vegetable oil in a 5MVA transformer.

Read more about Transformer Oil

What is the function of 5 MVA transformer oil?

1) Insulation properties

Increase the insulation strength of each component in the 5MVA power transformer. The oil of the transformer has good insulation strength and fluidity. It can fill all parts and any space of the transformer, and discharge the air, avoiding contact between the parts and the air, and affecting the insulation strength. Between the windings and the tank shell to maintain good insulation.

2) Heat dissipation performance

Transformer oil cools the core and windings of the transformer. During the operation of the transformer, the temperature of the oil near the winding and the iron core rises after being heated, the volume expands, and the specific gravity decreases and rises. During the cycle, heat is dissipated to the cooling device, which cools the core and windings.

3) Anti-corrosion performance

Transformer oil can keep insulators (such as wood, etc.) the original chemical and physical properties, and make metals (such as steel, etc.) play a role in anti-corrosion.

5 MVA Power Transformer Weight

Different voltage levels have different transformer weights. Generally, the higher the voltage level, the heavier the quality of the transformer.

Normally, a 5MVA 13.8KV power transformer's oil capacity is about 1850kg (4070 lbs), and the total weight of the 5 MVA transformer is about 9000kg. The 44kV 5mva transformer weight is about 11000kg, and the weight of transformer oil is about 2500kg.

5 MVA Transformer Parts

5 MVA transformer parts include a body (iron core, winding, insulated wire), transformer oil, oil tank and cooling device (cooling fan and radiator), pressure regulating device, protection device (moisture absorption device, safety air passage, gas relay, oil conservator) And temperature measuring devices (oil level gauge and dial thermometer), etc.

Read more: Overview of Oil-Immersed Distribution Transformers

5MVA Transformer Specification

Reading more about Transformer Specification

5 MVA Transformer Testing

Each transformer produced by Daelim must undergo strict tests before leaving the factory, and can only be shipped to customers after all tests meet the standards.

Keep reading: How to test a power transformer?

So, what test items will there be for 5mva transformers?

1. General Check

The Appearance is clean and no scratches or smears; the markings are clear;

2. The Connection is right in accordance with the Drawings;

3. Mechanical Operation Test；

4. Insulation Resistance Measurement;

5. Voltage Ratio Measurement& Vector Group Code Verification;

6. Winding Resistance Test;

7. Power- frequency Withstand Voltage Test;

8. Induced Voltage Withstand Test;

9.No load Loss and No Load Current Measurement;

10.No load Loss and No Load Current Measurement;

11. Seal Test

The above are all routine test items for transformers. If you have special test items requirements, such as temperature rise, short circuit, etc., Daelim Transformer can also do it.

Why transformers are used in MVA?

MVA is the capacity unit of the transformer. We will use MVA for large-capacity transformers, which is not very common. The common capacity unit of transformers is kVA, which is generally used in small and medium-sized transformers. So what is the direct relationship between MVA and kVA? They can be converted, 1000kVA=1MVA. Then the 5000kVA transformer is also called the 5MVA transformer. Therefore, high-voltage transformers and large-capacity medium voltage transformers are often represented by MVA, such as 13.8kV 10MVA transformers, and 69kV 25MVA transformers.

Read my article on the 10.5MVA-13.8/2.4kV Substation Transformer 

Why kVA is used instead of kW?

First, we need to understand the definitions of kVA and kW and the relationship between them.

The guaranteed value of the output capacity of the transformer in the rated state, we usually express in kVA. It is a physical unit, and kVA is the apparent power or capacity of the transformer, which is the maximum transformation capacity of the transformer. kW is an active power, which refers to the active power consumed by your equipment (usually power equipment), kilowatt (kW) = kilovolt-ampere (kVA) multiplied by the power factor.

Usually, engineers design transformers without knowing the power factor of the equipment you are using, engineers supply a certain amount of amperage at a specific voltage. So if you buy a transformer, you must know the capacity and voltage of the transformer, which are the most basic parameters for the transformer.

Read on: The Ultimate Guide to 2500KVA Transformer 

What is the difference between MVA and MW?

MVA (Mega Volt-Amperes):

• Definition: MVA represents apparent power in AC circuits, calculated as the product of voltage and current (S = V x I).
• Components: It includes both active (MW) and reactive (MVAr) power.
• Unit: Typically used for power transformers to denote capacity.
• Usage: Reflects the total power capacity of the system, considering both resistive and inductive loads.

MW (Mega Watts):

• Definition: MW denotes active power in AC circuits, measured in watts (W), representing actual power consumed or supplied by electrical equipment.
• Role: Essential for performing work and maintaining operational efficiency in electrical systems.
• Independent: Represents the real power converted into mechanical, thermal, or other forms of energy.

Learn more: How to purchase a 2 MVA power transformer?

Conversion of MW and MVA

Active power P, reactive power Q, apparent power S, the relationship between them is represented by a right triangle, the hypotenuse is represented as apparent power (S), and the adjacent side of apparent power represents active power (P), the angle between them is (φ); the opposite side represents the reactive power (Q).

For three-phase circuits:

S=√3 UI=√(P²+Q² )

P=√3 UIcosφ=Scosφ

Q=√3 UIsinφ=Ssinφ

How Many Kilowatt Motors Can A 5MVA Power Transformer Bring?

First, calculate the rated output current value of the secondary side of the transformer according to the formula, that is, I=5000000÷1.732÷400=7217A.

Knowing the rated current value, then take 80% of the full load, which is the current value of 5773A. Generally, a three-phase asynchronous motor has 1 kW and 2A. In theory, if all motors run at the same time, only a 5773/2=2886 kWh load can be carried.

Through the above calculation, we can conclude that a 5MVA power transformer can drive a three-phase asynchronous motor with a total power of 2886 kilowatts at the same time.

Cooling medium for 5 MVA transformer

The cooling system of the transformer is determined by the type of the transformer:

1. The dry-type transformer is cooled by external air, so its cooling medium is air.

2. The cooling medium of oil-type transformers is transformer oil, silicone oil, etc., of which transformer oil is the main body and is divided into 25# and 45# oil for insulation. Now some energy-saving and environmentally friendly transformers, especially foreign-funded transformer factories, use new insulating oils such as silicone oil and silicone oil.

3. Now some large transformers are also cooled by sulfur hexafluoride, so the cooling medium is sulfur hexafluoride.

Learn more: The Ultimate Guide to 1500kVA Transformer

What are the cooling systems of a 5mva power transformer?

Oil Immersion Self Cooling (ONAN)
Oil-immersed air cooling (ONAF)
Forced Oil Circulation Air Cooling (OFAF)
Forced Oil Circulation Water Cooling (OFWF)
Forced Oriented Oil Circulation Air Cooling (ODAF)
Forced pilot oil circulation water-cooled (ODWF)

Learn more: The ultimate guide to ONAN transformers

How to choose 3 phase 5mva transformer cooling method?

According to the requirements of the transformer selection guide, the selection of cooling methods is recommended as follows:

1. ONAN

31500kVA and below, 35kV and below products;

50000kVA and below, 110kV products.

2. ONAF

12500kVA~63000kVA, 35kV~110kV products;

Products below 75000kVA, l10kV;

40000kVA and below, 220kV products.

3. OFAF

50000~90000kVA, 220kV products.

4. OFWF

Generally, the step-up transformers of hydropower plants are used for 220kV and above, 60MVA, and above products.

5. ODAF or ODWF

75000kVA and above, 110kV products;

120000kVA and above, 220kV products;

330kV and 500kV products.

Therefore, the cooling method of the 3-phase 5mva transformer can be selected ONAN, ONAF

Try for free: 3 Phase Pad Mounted Transformer-Daelim Transformer

What Other Factors Influence the price of a 5 MVA transformer?

The price of a 5 MVA transformer is influenced by delivery charges, the complexity of operational instruments, the cost of copper versus aluminum, and the inclusion of essential components like insulating oil and protective devices. These factors collectively determine the overall cost of acquiring and installing such equipment.

Try for free: The Ultimate Guide to the 1000 kVA Transformer

Applications

With the help of a 5 MVA transformer, renewable energy sources, such as solar panel fields, will have their output amplified and fed into the electrical grid.

These 5000 kVA transformers can be mainly applied to industrial, electrical, manufacturing, steel, offshore, commercial, electric power distribution, utility, public, and more.

Transformers Solutions for Industrial and Commercial Buildings

5 MVA Transformer Dimensions

In most cases, 5 MVA transformer dimensions are 108 inches. 

At the same time, its height is 84 inches followed by a width size of 96 inches.

A 5 MVA transformer weighs about 11339 kg. That is equivalent to the weight of a semi-trailer truck.

Moreover, a transformer rated at 5MVA (5000kVA) has an oil capacity of 3030 liters of 3,000 to 4,500 gallons, depending on the specific design and manufacturer. 

It's important to note that the oil capacity can vary depending on the specific transformer, so it's always best to consult the manufacturer's specifications or consult with an expert in the field.

How Much is a 5 MVA Transformer Price At Daelim Transformer?

Daelim's 5 MVA transformer price sets are available between $21,000 to $58,000.

With Daelim Transformer, you can be greatly assured that the 5000 kVA transformer meets or exceeds the requirements set out by the ANSI, IEEE, and CSA.

You can highly benefit from Daelim Transformer since they implement remote monitoring and management for all their power transformers

Because of Daelim's status as a market leader and innovator, its power transmission and distribution systems are highly trusted by utilities, industries, and public institutions, all over the world.

Ultimately, Daelim Transformer is always dedicated to finding solutions and enhancing electrical distribution for consumers, which will lead to safer and more dependable power networks.