Nomex® 400 Series Features Proven Performer—Nomex® 410
DuPont™ Nomex® 410, the original form of Nomex® paper, has earned a global reputation for its ideal balance of properties and proven performance in a wide range of applications.
For more than 50 years, Nomex® 410 has been addressing the ever-increasing demands of the electrical industry, making it the insulation of choice for a majority of today’s electrical equipment applications.
The papers in the Nomex® 400 Series, most notably Nomex® 410, have been an original benchmark product for performance, reliability and longevity—a benchmark by which all other insulating materials are compared.
What gives Nomex® 410 and the rest of the Nomex® 400 Series its superior characteristics is the ideal balance of five key properties:
- Exceptional thermal stability—Temperatures up to 200°C have little or no effect on the electrical and mechanical properties of Nomex®, and useful values are retained at considerably higher temperatures. What’s more, these useful properties are maintained for at least 10 years of continuous exposure at 220°C.
- Outstanding mechanical toughness—Densified Nomex® products are strong and resilient with good resistance to tearing and abrasion. Thinner grades are also flexible.
- Inherent dielectric strength—In densified form, Nomex® withstands short-term electrical stresses of 18 kV/mm (457 mil) to 40 kV/mm (1,015 mil), depending on product type and thickness, with no need for further treatment with varnishes or resins.
- Broad chemical compatibility—Nomex® is essentially unaffected by most solvents and is unusually resistant to attacks by acids and alkalis. It is compatible with all classes of varnishes and adhesives, transformer fluids, lubricating oils and refrigerants.
- Excellent flame resistance—Nomex® products do not melt and, with a limiting oxygen index (LOI) at 220°C above 20.8 (the critical value for combustion in normal air), they do not support combustion.
Nomex® 410 is used in almost every known sheet insulation application. This high-density product has high inherent dielectric strength, mechanical toughness, flexibility and resilience. It is produced in thicknesses ranging from 0.05 mm (2 mil) to 0.76 mm (30 mil), with specific gravities ranging from 0.7 to 1.2.
Nomex® 411 is a lower-density version of Nomex® 410. It is available in thicknesses ranging from 0.13 mm (5 mil) to 0.58 mm (23 mil), with a specific gravity of 0.3 and correspondingly lower electrical and mechanical properties. It is used in applications such as motor phase insulation and transformer coil end filler, where high bulk and conformability are of prime importance, along with increased impregnability and saturability.
Nomex® 414 is electrically and thermally similar to Nomex® 410, but it is manufactured to produce a strong but more flexible and conformable sheet with an open surface. It is produced in thicknesses ranging from 0.18 mm (7 mil) to 0.38 mm (15 mil), with specific gravities ranging from 0.9 to 1.0. It is designed for use as slot insulation in hand-wound motors, for linear wrapping of wire, and as main insulation for dry-type transformers where conformability and impregnability are required.
Nomex® 416 LAM
Nomex® 416 LAM is a paper designed for use in electrical flexible laminate insulation. It is produced in three thicknesses: 0.05 mm (2 mil), 0.08 mm (3 mil) and 0.13 mm (5 mil). Nomex® based laminates are used to create high-integrity electrical insulation for motors, generators and transformers. Several laminate constructions exist. The most common are NM and NMN, where Nomex® paper and polyester film are used; and NK or NKN, where Nomex® paper and polyimide film are used.
Nomex® 464 LAM
Nomex® 464 LAM is a lightweight paper compared to Nomex® 416 LAM, but is intended for the same use in electrical flexible laminate insulation. It is available in 0.05 mm (2 mil). Similar laminate constructions can be found in the market, with either polyester film or polyimide film, depending on the thermal requirements of the application.
Typical Applications for Nomex® 400 Series
- Large power, medium voltage and high voltage (>1.2 kV)
- Medium voltage, general purpose (>1.2 kV)
- Medium voltage, substation (>1.2 KV)
- Low voltage, general purpose/specialty (<1.2 kV)
- HVT/microwave power
- UPS/data center/converter
- Lighting ballast
- Power conversion
Seeing the excellent electrical, mechanical and thermal properties of Nomex® 410 makes it easy to understand why this insulation paper is widely used in a majority of electrical equipment applications.
- ABB’s Rapid Recovery Transformer Initiative
- ABB’s first 250 MVA, 400 kV fastdeployable transformer
- Reliability and high temperature performance in Nuclear Power Plants
The use of Nomex® paper and pressboard helps enable a lighter weight traction transformer design for Amtrak’s Acela Express, reducing the weight of the equipment transformer by between 15% and 25%.