Dry Type Transformers

When evaluating your dry type transformer inventory, understanding the options will make choosing the correct setup for your business simple. Our ELSCO inventory includes several options, including in-stock dry types that can be customized for your exact set-up as well as custom build to order units, for seamless integration into existing enclosures. Discover how our range of medium voltage transformers can help your business save time and money in a change out/upgrade or emergency.


What Is a Dry Type Transformer?

A dry type transformer does not use a liquid cooling agent. Instead of oil, circulating air protects the coils – windings and insulation – from overheating. Within the transformer, manufacturers have multiple options for the components used for insulation, windings and core materials. The type of insulation and windings contribute to the unit’s longevity, so when selecting customized transformers, consider the choice of materials carefully.

For instance, when selecting windings, copper lasts longer than aluminum and conducts electricity better. Insulation options must withstand operating temperatures, offer mechanical and dielectric strength and avoid thermal shock damage. The core material used should reduce hysteresis loss and have a high permeability. Too much hysteresis loss leads to energy loss from the system as heat.

Dry type electrical transformers have many variations in their windings and materials, such as round coil or rectangular coil, disc wound or layer wound and copper windings or aluminum windings.

Round or circular coil windings offer greater strength for medium and higher voltage transformers compared to rectangular coil designs.

Using insulated conductor wound around combs or key spacers, the disc wound type of transformer winding is common in core-form transformers that have 25kV or higher classifications.  Since it is the superior design, we utilize it in our 5 kv & 15 kV designs.

Elsco dry type transformers use the preferred copper conductor in our designs. Copper provides high-quality conduction and mechanical strength, making it the ideal metal for all but the smallest transformer models.

The Benefits of Dry Type Transformers

The benefits of our dry type electrical transformers originate from both the design and materials used for the device’s constructions.

1. Superior Materials

The new, in-stock and build to order transformers we offer have high efficiency designs which save you money month after month versus used or reconditioned units.  Our new dry types provide a balance of cost-effectiveness, quiet operation and advanced performance. Coil options include copper or aluminum magnet wire and round coil, disc wound designs. Additionally, we select insulation such as Dupont Nomex and SG200 fiberglass for their quality and outstanding longevity.

In our inventory, we have dry type transformers from 500 kilo-volt-amperes (kVA) to 2,500 kVA, and we can produce custom units up to 4,000 kVA. Our in-stock units have primary voltages of 2400, 4160, 12470, 13200 or 13800.

2. Long Life

When using quality materials in the transformer construction, dry type units can last for years with little to no maintenance required. Their resistance to short circuits and excessive heating keeps these units working well for years.

3. Lower Fire Risk

Enclosing the coils in a polyester varnish coating isolates them from moisture and from producing a fire hazard. Consequently, dry type models provide a better option in fire-risk areas such as forests, petrochemical plants or chemical manufacturing facilities.

4. Easy Installation

With options for indoor and outdoor enclosures, the installation of these transformers is more straightforward than other types. Choosing one with the most uncomplicated installation will cut down on waiting time until your operation can utilize the new transformer. In fact, we can create a customized model that will offer a plug and play retrofit installation in your facility as a direct replacement for an old transformer.

5. Pollution Free

Without oil inside them, dry type electrical transformers do not have anything that can leak out and contaminate an area. These models provide pollution-free operation, making them useful in areas sensitive to liquid/chemical contamination.

6. Suitable for a Variety of Environments

Because many models provide moisture protection of the inner coils or cores, these transformers can work indoors and outdoors in dry and moist conditions. Plus, they have proven performance even through some seismic events. In areas prone to earthquakes, building codes may require equipment to have such protection against damage from seismic activity.


How the Right Transformer Setup Will Save You Money Long-Term

Choosing a quality, well-built transformer setup will save you money over time. By making specifications with an eye toward longevity, you can extend the time between transformer replacements and repairs. Over time, your business will spend less money on maintaining transformers over the life of the building. Longer lasting options include choosing dry type models and specifying components that contribute to fewer failures. Dry type electrical transformers can last longer compared to oil-filled models provided you have the superior design characteristics and quality materials.

Additionally, the former will have fewer winding failures. The quality of the construction of the unit matters, too. Trust a well-known manufacturer with a record of reliable transformers and durable parts. ELSCO Transformers fulfills this criteria with our history of high caliber production that lasts beyond our extra-long warranties. With our three-year or five-year warranties, you pay less for repairs because you get more time to have us make repairs covered under the warranty.


Dry Type Transformer Specifications

We proudly produce all our transformers in the United States. The primary windings are a round coil, disc wound design utilizing a slotted comb design with either heavy armored polythermaleze (HAPT) covered wire or Nomex-insulated copper magnet wire. For secondary windings, we use Nomex insulation with strip-wound copper conductors, which eliminate vertical forces. Our dry type units have a basic insulation level (BIL) rating equal to liquid-filled units.

For easier installation, our transformers can have customized bus work or retrofit designs. Additionally, we also stock and can provide fans and digital temperature controllers with thermocouples.

To create a transformer for a specific application, you can customize the following options:

  • Core and coil assemblies
  • High short-circuit strength designs
  • Faraday electrostatic shields
  • K factor designs
  • High Voltage ratings- 2400, 4160, 12470, 13200, and 13800 Delta in stock.
  • Low Voltage ratings- 208, 480, 2400, and 4160 volts.

Dry Type Transformer Applications

Our catalog of transformers fills numerous applications and can work in different locations. For example, we offer NEMA 1 and NEMA 2 indoor enclosures. For outdoor spaces, we have NEMA 3R enclosures with strip heaters.

Applications of our transformers include providing power services to the following businesses:

  • Industrial utility companies
  • Healthcare facilities
  • Colleges and universities
  • Correctional facilities
  • Electrical contractors
  • Manufacturers
  • Electricity supply houses

The ELSCO Transformers Dry Type Transformer Warranty

We have two warranties for our transformers, depending on whether the unit was new or remanufactured. Our new transformers carry a five-year warranty that guarantees against any workmanship defects or material problems under regular use. You must properly install the unit to ensure adequate airflow. If you choose to add thermocouples and fan controls, the former’s leads must be at least 6 inches from the bus bar and high voltage coils.

On our remanufactured units, we provide a three-year warranty. The requirements to avoid voiding the warranty for remanufactured transformers are the same as for new models. You must correctly install the model and place the thermocouple leads far enough from the bus bar and high voltage coils.

In 1988, we started building our dry type transformers. Since then, our products have experienced zero failures or warranty issues. We can attain such high reliability and offer these extended warranties because we use superior components and expert workmanship in all our transformers. With parts such as Dupont Nomex insulation, SG200 fiberglass insulation, 100% copper windings and round coil, disc wound design, we set our transformers apart from the rest.

Contact ELSCO Transformers for Dry Type Transformers

Your business deserves a reliable and trustworthy service. Trust us at ELSCO Transformers, the leading full-service company for medium voltage transformers in the industry. With warranties that outlast the competition, high-quality transformers and custom builds, you will find the new or replacement dry type transformer you need. Orders on new dry type units typically quick ship, meaning they leave our facility within 24 to 48 hours. For more information about our products, answers to your questions or to start customizing a transformer for your operation, contact us at ELSCO Transformers.


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