69kV Transformer 500 kVA

There are many transformer types in the market, and one of them is the 69kV transformer and transformer 500 kVA. This type of transformer is generally used in a wide range of industries and utilities. Electrical professionals employ a variety of components to establish an efficient and secure flow of electricity. Often, 69kV transformers and transformer 500 kVA are made with high-grade materials and modern manufacturing systems. This way, these transformers can last a long and conflict-free life.Daelim can provide you with a variety of transformers up to 500 kVA amd 69kv, such as: Power Transformer, Three Phase Oil-immersed Distribution Transformer, Dry-type Transformer, Pad-Mounted Transformer and Single-Phase Transformer, etc. With more than 15 years of experience in the design, engineering, and production of high-quality electrical products and equipment, we can provide you with a variety of standard, expert, and customized services.

DAELIM offers a wide range of power and liquid-filled transformers that meet international standards like ANSI, IEEE, and CSA. For 15 years, DAELIM has continuously provided clients with high-quality transformers built using state-of-the-art technology.

CSP Type Single Phase 69kV Transformer 550 kVA
Oil Immersed Three Phase Distribution Transformer
Three Phase Dry Type 65kV Transformer 500 kVA
75-5000 kVA Three Phase Pad Mounted Transformer

69kV Transformer 500 kVA: The Ultimate FAQ Guide

What is 69kV Transfomer?

69kV power transformers are a type of oil transformers used in substations. Generally, these are medium-power transformers designed to optimize transformer cores, coils, and other components. They are also often built by domestic and foreign technologies for better durability.

Besides this, 69kV transformers also adjust the voltage of their system for better operationality. Depending on what you need, these medium-power transformers can be customized for your electrical system.

69kV Transformer’s Standard Features and Capacities

As mentioned earlier, transformers are solid-state equipment designed to convert energy from one voltage to another. Depending on the type of transformer you’re looking for, you can find different features and capacities to suit your needs. If you’re unsure about the transformer you’re going to acquire, here are the characteristics of a 69kV transformer.

69kv transformer 500 kVA


Ampacity is the term used to describe the maximum current carrying capacity of specific equipment. Measured in amps, it’s determined as the total current a cable can tolerate before it overheats. A 69kV transformer generally has a power rating of 25000 kVA, which means that it is suitable for 209.18 amps.

Phase Type

Transformers can be classified into two phase types: single-phase and three-phase. 69kV transformers are a type of three-phase transformers. Three-phase transformers usually have three lines of power and can come in different types:


Encapsulated transformers are helpful for various loads. These are also often used for indoor and outdoor applications for commercial and industrial uses. Generally, three-phase encapsulated transformers have ratings that range from 3 to 75 kVA.


Like encapsulated transformers, ventilated transformers can be used in many indoor and outdoor loads. These are also used for industrial and commercial applications. However, unlike encapsulated transformers, ventilated ones have higher ratings of up to 1,000 kVA.

Enclosed and Non-ventilated

Unlike the first two types of three-phase transformers, industries use enclosed and non-ventilated transformers in high-dirt and high-debris environments. Generally, these transformers have a rating of about 25 to 500 kVA.

On the other hand, single-phase transformers have a single-phase alternating current and two tines of alternating current power.


69kV transformers are for those who want high-quality transformers for various uses. One great feature of the 69kV transformer is its high-voltage cover-mounted bushings. These transformers also have liquid level and liquid temperature gauges. Unlike other transformers, 69kV transformers have a low partial discharge, low loss, high-reliability factor, and are lightweight. 

Aside from these, 69kV transformers have highly absorbent cores that help deliver their purpose. Additionally, since 69kV transformers are oil transformers, its oil preservations system uses a sealed diaphragm. This conservator system allows the transformer to have a moisture-proof barrier that resists oil, making it durable and highly functional.

Cooling System

69kV transformers have a forced-air cooling system, which provides the transformers with automatic three-phase motor fans. This way, the various components of the transformer, including its fan motor, have thermal protection. Generally, the cooling fans are mounted on radiators with a control box mounted on the tank’s wall.

Common Applications for 69kV Transformer

The winding of the transformer can lower or increase voltages. Depending on the winding present in the transformer, it can serve different applications in many industries. Generally, industries usually use medium-voltage transformers where you need large amounts of power. Besides this, you can also use a medium-voltage transformer in the following:

Data Centers

Industries use medium-voltage transformers in data centers to avoid data loss caused by power outages. Generally, firms install their transformers as close to the substations to maximize operational efficiency and reduce costs.

Large Facilities

Extensive facilities, like campuses, high-rise structures, and warehouses, use medium-voltage transformers. These help in centralized cooling and with long feeder lines. Additionally, medium-voltage transformers also increase usable footage space in these facilities.

What is 500 kVA transformer?

Transformers are essential, most especially for high voltage distribution lines. These devices are responsible for converting an alternating current from a specific voltage to a desired one. Additionally, transformers can either use “step-down” or “step-up,” a voltage output that works under the principle of magnetic induction. 

Electricity is distributed to long-distance networks through high-voltage currents. However, these high-voltage currents can be hazardous and cannot be utilized for commercial or residential use. Thus, these voltages need to be “transformed” to lower consumable ratings.

The same distribution method goes with power suppliers. However, they step up the voltage to make long-distance distribution possible.

The industry measures the power capability of these components through kVA or kilovolt-ampere. Kilovolt-ampere stands for the apparent power of an electric current. In which different power requirements specify capacity ranges to perform the voltage conversion.

In this context, transformer 500 kVA means a transformer capable of handling power thresholds within the 500kVA rating. Typically, these ratings mean that the Single-Phase Transformer can process power ratings equal to or lower than that number.

There  are international standards for widely used kVA ratings for transformers. You can contact your local manufacturer for more details about the other ratings. 

69kv distribution transformer 500 kVA

Common Types Of Transformer 500 kVA

We can categorize transformer 500kVA between two types: single-phase and three-phase transformers. Choosing between these two can be essential for the compatibility of components within an electrical system.

Most 500 kVA Single-Phase Transformer are three-phased since they fall on the higher rating spectrum. However, some demands require a single-phase variant. Thus, resulting in still existing production of single-phase variants.

Aside from the type of phasing, manufacturers further break down their classification on the way they are built. Certain types of casing and structure are configured to fit the installation environment. For distinction, below are some of the key differences between the two phases and their respective application and builds.

Single-Phase Transformer

A single-phase transformer is the basic type of transformer. There are only two coils or windings necessary to convert currents. This type only includes an input and an output coil to distribute power.

A Single-phase transformer is usually recommended for residential or commercial use. However, a few designs are also capable of handling low to medium industrial demands.

Below are a few single-phase transformer variants available in the market:
1. Encapsulated
This type is common for low-rating transformers. Typical rating ranges include 50 VA to 25 kVA. Additionally, this is commonly used for general loads, including both indoor or outdoor loads. Transformers of this type can also be banked or configured to function as a three-phase alternative. Common applications span from residential to industrial utilities.
2. Ventilated
A ventilated transformer is ideal for multiple loads both indoors and outdoors. With ratings ranging from 25 t0 100 kVA, it is commonly used for residential and residential systems.
3. Full-Close, Non-Ventilated
Full-Close, Non-Ventilated transformer types are best for the “dirty” or “dusty” installation places. The full-closed casing prevents harmful substances from blocking or intercepting their functions. They rate around 25-500 kVA.

Three-Phase Transformer 500 kVA

Three-phase transformers work under a different concept of power generation. It uses a three-coil system that is spaced 120 degrees apart, which is called “Delta.” This system produces power by rotating the delta within the magnetic field. The generated output is then sent through 3 output lines. Hence, the term “three-phase” system.

A three-phase transformer 500 kVA is advised for industrial applications. The power generating system of a three-phase transformer is more efficient for long distribution lines. Thus, you can expect a more efficient power distribution in industrial applications. In which, power lines can significantly be distant than residential or commercial ones.

Furthermore, certain heavy machinery may also require a three-phase system. Some even standardize the use of such. Thus, in all accounts, a three-phase transformer 500kVA is best for industrial usage.

Similar to the single-phase variant, three-phase transformers can be categorized according to the following build:
1. Encapsulated
This type is applicable for a variety of loads, including both outdoor and indoor sources. Typical rating ranges include 3 VA to 75 kVA. Application is similar to the single-phase variant. However, most designs are capable of handling higher rating demands.
2. Ventilated
A ventilated transformer is ideal for multiple loads both indoors and outdoors with applications similar to the single-phase variant. Although, the three-phase version caters to up to extremely high ratings reaching 1,000 kVA.
3. Full-Close, Non-Ventilated
The best for more contaminated or dusty environments. The same application and design as with the single-phase variant. The rating, however, spans from higher 25 to 500 kVA.

These typical market designs and manufacturing variations are still prevalent. But many electrical component companies are innovating to meet the ever-growing demands of the industry. Thus, in doing so, plenty of designs with usually higher ratings is possible for both types of transformer.

Also, please make note that single-phase and three-phase transformers systems have different manners of kVA computation. This consideration will be vital in your load’s computation prior to determining your transformer size. You may check how to compute their respective kVAs with the computation guide in the next section of this article.

How to Determine if I Need a 500 kVA Transformer?

Before proceeding with the actual computations, it is important to be familiarized with the terms and units involved.

First, volts-amperes (VA) or kilovolts-amperes (kVA) represent the unit of the apparent power. Smaller transformer sizes use VA as a unit and are important to note to avoid confusion among purchases. Furthermore, kVA stands for the ‘apparent power’ and not the ‘real power’ of the current represented by Wattage.

Apparent power is practically the face value of rating without thresholds and losses concerned. Meanwhile, real power is the usable or drawable power from the device. Real power is typically within a fraction of the apparent power capacity.

Determining the right transformer rating is vital for both safety and power efficiency. Below rating transformers can result in conversion failure or even overheating. Meanwhile, the above rating transformer can be better but may not be cost-efficient depending on its use.

Thus, below are a few steps to use in determining what transformer size is actually needed.

How to Calculate kVA?

  1. Determine the Load Voltage (Volts)
  2. Check the load current (Amperes)
  3. Check line voltage
  4. Then verify your use, whether it is single or three phases. Below is the respective formula to use:


Single-Phase: Volts x Amps /100 = kVA

Three-Phase: Volts x Amps x 1.732 /100 = kVA


If the kVA of the load is equal to or less than 5kVA, then the transformer 500kVA fits the job. The kVA of the transformer should always be higher than the load to process current and future requirements.

What Is the Difference Between kV and kVA?

kV and kVA are two quantities used in electrical engineering. kV, or kilo Volts, is measured in Volts in the 10^3 order. On the other hand, kVA, or kilo Volts Amperes, refers to the total power input in a system.

Besides these, there are also other differences between the two.


  • Refers to KiloVolts
  • 1 kV = 1000 Volts
  • Measures electrical pressure and half of power


  • Refers to Kilo Volt-Amps
  • One kVA = 1000 Volt-Amps
  • Measures the potential energy a system can provide
  • It is expressed as Watts when consumed
  • Typically used in rating transformers

What Is a High Voltage kV?

Depending on where you live, voltage classifications and ranges change. For instance, the United States follows the National Electric Code (NEC) and the National Electrical Manufacturer’s Association (NEMA). These organizations provide guidelines and standards in terms of voltage classification.

Generally, systems with high-voltage kV are often composed of 230-kV to 345-kV equipment. Typically, these have two direct current (DC) lines, which are comprised of 400-kV and 500-kV. Transformers with high-voltage kV increase voltage to transmission voltage, including 69kV. This way, the energy can travel long distances through high-voltage transmission.

What’s The Difference Between a Power Transformer and a Distribution Transformer?

As mentioned, transformers convert voltages to serve many purposes. You can find two types of transformers in the market: power transformers and distribution transformers. There are many differences between the two, which you can see below.

Power Transformer

  • ower Three-Phase Transformer  transmit and receive power. Their voltage ratio usually ranges from 756kV to 11kV and has a higher MVA rating than distribution transformers.
  • They are used in applications that require higher voltages.
  • You can find power Three-Phase Transformer  in different ratings, including 33kV, 66kV, 200kV, and 400kV.
  • These transformers operate on full load and have minimal load fluctuations. Additionally, power transformers are designed to consider maximum efficiency (100%), determined by the power output/input ratio.
  • You can often see power transformers in transmission substations and power generation stations.
  • Power transformers are larger compared to distribution transformers.

Distribution Transformer

  • Unlike power Three-Phase Transformer , industries use distribution transformers for energy circulation. Thus, distribution transformers decrease voltages and the incidental level of power transmission lines. These usually have a voltage range of 33kV to 430kV.
  • The voltage ratings of distribution transformers usually range from 11kV, 3.3kV, and 230 volts.
  • This type of transformer operates at lower loads than power transformers. 
  • Compared to power transformers, distribution transformers only have a maximum efficiency rating of 50% to 70%. 
  • You can often find distribution transformers where power needs to be distributed in industrial or local functions.

Can you use single-phase transformers on a three-phase source?

The short and simple answer is yes. Because transformers aren’t phase-changing equipment, a single-phase transformer can’t change into a three-phase transformer and vice versa. However, you can use a single-phase transformer on a three-phase source because connections can be made compatible with the source.

What you have to do is connect three single-phase transformers to create one three-phase transformer. You can also use a pre-assembled three-phase transformer consisting of three windings.

Do you have to ground a transformer?

In most cases, you have to ground the enclosure of transformers for safety reasons. Also, keep in mind that transformers can’t operate correctly if you don’t ground them.

With this, it’s important to do more research about ground requirements and other electrical codes.

Why do transformers produce noise?

Transformers hum due to magnetostriction, the extension of magnetic sheet steel due to magnetization. When the sheet steel is no longer being magnetized, it goes back to its original state. Since voltage and current are alternating inside the transformer, it extends and contracts, which produces the humming. 


Getting the right rating of the transformer allows for better power utilization. It also saves you from the risks and hassle of damage repair and faulty performance. Besides, high-quality transformer performance is necessary for any smooth distribution of electricity. It is also important to choose the right specification to meet the demands of your application.

Since extensive facilities need a significant amount of power, transformers must convert energy into valuable electricity. With this, a 69kV transformer can be of great help if you’re looking for a medium-voltage transformer. It can serve many purposes, including the prevention of data loss and efficient energy transmission.

Ultimately, the product should come from a reputable brand attested by years of experience and expertise like Daelim.

Daelim Belafic is the leading brand of transformer manufacturer in China. Backed with a decade of good field reputation, it established itself as one of the trusted electric brands worldwide. If in search of a quality transformer 500 kVA or other electrical components, look no further; Daelim has it.

Daelim Belafic is your innovative and reliable partner for electrical products and solutions.
Contact us today for further inquiries or collaboration.