250 KVA Transformer, Everything You Need to Know

Electrical power is a necessity in the world today. It’s used to power our homes, businesses, and critical infrastructure. Ensuring that the right amount of electricity is delivered to where it’s needed is essential for a functioning society. That’s why transformers are so important. A transformer is a device that helps regulate and manage electrical current. They come in all shapes and sizes, but one of the most common types is the 250 KVA transformer.

If you’re looking to install or upgrade a 250KVA transformer, then this guide is for you. Also, this type of transformer is available in DAELIM. The company has established itself as one of the top manufacturers of high-quality transformers for over 20 years. You’re sure the company follows international standards such as ANSI, IEEE, IEC, CSA, and AS/NZ with their products.

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

Dry-type Transformer

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

Table of Contents

What Is a 250KVA Transformer?

dry type 250 kva transformer

The load-controlling transformer is designed and manufactured to meet market demands. It can be widely employed in rural, urban, industrial, and agricultural power networks. Moreover, it is very important to save energy and protect the environment.

The iron core of this product is laminated in a ladder form instead of the typical lamination technology. Thus increasing the dispersion of magnetic circuits inside the core. It might be considered a revolution in transformer iron core production with its short-circuit strength and capability. The tank design of the outer shell is also durable and lovely.

A transformer 250KVA has high reliability, performance, economic indicators, and a fair price. Sometimes DAELIM uses a three-joint phase-shaped core, curing paint by brushing the surface to prevent visible wear and tear. Moreover, DAELIM’s new oil road design’s winding structure is reasonable, with enhanced insulation to increase mechanical performance.

250 KVA Transformer Specification

250 kVA transformers are heavy-duty electrical devices used to step down high-voltage AC power to a lower voltage level. They’re typically used in industrial or commercial applications, where large amounts of power need to be handled.

The transformer has a 50Hz frequency. A transformer operating at 50Hz creates 20% more flux lines. As a result, a transformer with 50Hz will simply run cooler. Additionally, the transformer uses different cooling methods. But the most common ones are ANAF and ONAN.

The percentage impedance of this type is 4.5% ± 10% at 75°C. While its maximum temperature rise over ambient is as follows:

  • 35°C – top oil temperature (measured by a thermometer)
  • 40°C – winding temperature rise measured by resistance

The maximum standard total losses at 75°C are 980 Watts for 50% loading and 2,930 Watts for 100% loading. There should be no positive tolerance for the total allowable losses mentioned. Another great specification of this type of transformer is the maximum temperatures. Here are the temperature conditions that a 250 KVA transformer needs to function at an optimum state:

  • 50°C – maximum ambient air temperature
  • 40°C – maximum daily average ambient
  • -5°C – minimum ambient air temperature
  • 100% – relative humidity

On the other hand, the transformer can withstand 12 KV as the highest system voltage. It can also withstand a rated lightning impulse of 75. The two are based on a nominal voltage of 11 KV. Additionally, the rated short duration power frequency withstand voltage is 28 KV and 3 KV. The data is based on the nominal voltage of 11 KV and 433 KV, respectively.

Types of 250 KVA Transformer

250 KVA Oil immersed transformer

Various types of 250 kVA transformers are available on the market, with different features and specifications. Some common features include dry-type or oil-filled construction, hermetically sealed enclosures, and tap changers. When choosing a transformer, it is important to consider the specific needs of your application to select the best one.

250 KVA Dry Type Cast Resin Transformer

250 kva Dry Type Cast Resin transformer

A dry-type cast resin is one of the types of 250 KVA transformers with excellent performance. DAELIM produces a complete line of cast resin dry-type transformers that provides excellent insulation and environmental protection. Moreover, when combined with the foil winding technology, it provides top-quality dielectric performance and short circuit withstands. It ensures long-term reliability for both distribution and special applications.

The core is high-quality grain-oriented cold-rolled silicon steel with strong magnetic conductivity. It has a low partial discharge, low noise, and low loss. Additionally, this type has a high anti-lightning impact level and strong anti-short circuit capacity.

It has excellent moisture resistance for operation at 100% relative humidity. Also, it makes a perfect transformer for long-term operation at 150 percent loading as it has a strong overload capability.

250 KVA Oil Immersed Transformer

250kva transformer

The full-sealed oil-immersed 250 KVA transformer meets international technical parameters and standards. Its coil is constructed of quality oxygen-free copper, and its core is built of quality cold-rolled silicon sheets. The core also has a full-mitter non-puncture construction. It’s commonly employed in industrial and agricultural networks for transmission and distribution.

The device is extremely energy efficient with relatively low eddy current and hysteresis losses. It also has a free-breathing and leak-proof design and is free of partial discharge. The design is extremely low noise, compact, and almost maintenance-free to meet local regulations.

A large-capacity device like the 250 KVA transformer can carry power over long distances while eliminating energy waste. It has an energy efficiency of up to 99.44 percent and functions constantly and reliably 24 hours a day.

Additionally, the transformer is constructed of high-quality, environmentally safe materials for long-term durability and impact resistance. The three-phase oil-immersed transformer 250kVA, in particular, has high short-circuit resistance, high lightning protection, and long and high overload resistance.

250 KVA Power for Mining

When mining for cryptocurrencies, one of the most important factors is having a reliable and efficient power supply. That’s why many miners choose to use a transformer 250KVA power system.

These systems are designed specifically for Bitcoin mining, and they offer a number of advantages. First, they’re highly efficient, meaning that you’ll be able to mine more Bitcoin with less power. Second, they’re also very scalable, so you can easily add more mining rigs as your operation grows.

Finally, a 250 KVA mining power supply is also very affordable, making it a great option for small-scale miners. If you’re looking for a reliable and cost-effective solution for your Bitcoin mining, a 250 KVA system is worth considering.

What is the current rating of a transformer with a capacity of 250 kVA?

types of 250 KVA transformers

The ratings of transformers are determined by two criteria, not merely the power rating.

You must know the voltage level.

The transformer rating is expressed in both KVA and Voltage. For example, you have a 250 KVA 3-phase transformer rated at 11kv/415v. The primary full-load current is 13,121.982 A, and the secondary full-load current is 347.812 A.

What's the distinction between an oil and a dry transformer?

250 KVA transformer

Air is used to cool dry-type transformers, while oil is used to cool oil-filled transformers. Oil-filled transformers are more efficient than the other type because it has a lower voltage rating and is smaller.

As a result, the dry type is significantly more likely to overheat during overload. It’s crucial to remember that performance is limited during overload. As a result, maintaining the power supply of dry-type transformers is more expensive over time.

Is 1 kVA sufficient for household use?

250 KVA pole Transformer

The electricity delivered by your meter (9.2 kVA on average) should be enough for routine energy use. However, it only theoretically allows you to supply devices with a maximum power of 9.2 kW (9200 watts) simultaneously.

In a typical modern 3-4 bedroom home, the average demand is roughly 80-100 amps. That is, if diversity is not taken into account, the average should be 18.4 – 23 kVA.


The 250 KVA transformer is a reliable, high-performing, and economical choice for your business. It can be widely employed in a variety of settings, saving energy and protecting the environment along the way.

With its fair price and wide range of benefits, this load-controlling transformer is an excellent investment for your company. Have you considered using a transformer 250KVA in your business? If not, now may be the time to make the switch.

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