Types of Insulation Used in Dry Type Transformers

The insulation material in a transformer matters because it affects the transformer’s capacity, life span and cost. Insulation options for transformers vary by transformer type — liquid-filled or dry type. Understanding these options can help you choose a quality-made transformer with a long performance life.

Insulation Used in Dry Type Transformers

Transformer manufacturers have several options for insulation for dry types, including:

Conventional varnish: Coated insulation requires dipping the component in a varnish or resin for adequate protection in moderate-use applications.
Vacuum Pressure Impregnated (VPI) varnish: VPI varnish protects the coils from moisture and contamination by permeating the winding with varnish.
Vacuum Pressure Encapsulated (VPE) varnish: VPC varnish eliminates the voids that can cause electrical discharges, such as corona, by embedding the winding in resin under vacuum pressure.
Cast coil: For cast coils, the transformer winding is placed in a mold and cast in resin. This option improves the coil’s short-circuit and mechanical strength, as well as its moisture and chemical resistance.

What Type of Insulation Is Used in Dry Types at ELSCO Transformers?

The dry type transformers from ELSCO Transformers use quality insulation components to effectively protect the system, yielding a typical service life of over 30 years. These systems have a basic insulation level rating equal to liquid-filled systems.

We choose insulation types known for quality and longevity to ensure excellent performance. Our builds use Dupont Nomex insulation with strip-wound copper conductors for the secondary windings. This insulation eliminates vertical forces on the transformer. ELSCO Transformers also uses SG200 fiberglass.

Benefit From an Industry-Leading Warranty on Dry Type Transformers

Our warranties for dry type transformers are among the best in the industry. Where other manufacturers offer an average warranty of one year, we provide extended coverage because our systems are highly reliable and utilize the best components and craftsmanship. Since 1988, our dry type transformers have experienced zero warranty issues.

New transformers have a five-year warranty for indoor use in a clean and dry environment for workmanship defects and material problems. Remanufactured transformers carry a three-year warranty. For these warranties to remain valid, you must correctly install your transformer and have the unit’s leads at least 6 inches from the high-voltage coils and bus bar.

Contact ELSCO Transformers About Insulation for Dry Types Today

Types of Insulation Used in Dry Type Transformers

ELSCO Transformers manufactures reliable medium-voltage dry type transformers. Hospitals, universities, electrical supply houses and other industries rely on our transformers for energy efficiency and long service life.