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Electrical Insulation Systems Testing and Certification

Our comprehensive services can help verify that your insulation materials will perform safely in a shared environment — a critical requirement of any complex electrical system.

Various insulation materials that are used in electrical systems.

Electrical insulation testing and certification solutions for complex electrical systems 

Today’s complex electrical systems demand greater diligence in verifying that individual insulation materials can, and will, perform safely in shared environments. If you work in the electrical insulation systems industry, our comprehensive testing and certification services can help you.

An electrical insulation system (EIS) is comprised of a unique combination of materials that have been verified for chemical compatibility when used at certain maximum temperatures. These combinations are arranged to form EIS, such as those used in motors, transformers and solenoids.

We offer General Purpose Model (GPM) testing and assembly. GPM, formerly known as motorettes, are nonfunctional test samples designed specifically for test purposes. A GPM represents all of the major electrical insulation materials of a functional product, such as the ground/interwinding insulation and winding wires. Nonfunctional test samples offer many advantages over the testing of functional samples, such as the ability to test multiple alternative insulation materials and wire types simultaneously. We test both functional and nonfunctional samples in accordance with UL 1446 the standard for systems of Insulating Materials, and IEC 61857-21. 

Additional electrical insulation testing standards

In addition to evaluating these products for certain common physical properties, we can evaluate them for specific end-use applications, e.g., enclosures for electrical equipment, motor fuel dispensing devices, etc., when the governing standard has requirements that differ from ANSI/UL 157. We also test to IEC 60085 electrical insulation – thermal classification, and ANSI/UL 1446 the standard for safety of systems of insulating materials – general, for the U.S. market.

Other standards that may be used, where appropriate, include:

  • The Test Procedure for Thermal Evaluation of Insulation Systems for Dry-Type Power and Distribution Transformers, Including Open-Wound, Solid-Cast, and Resin-Encapsulated Transformers, IEEE C57.12.60;
  • The Standard for Rotating Electrical Machines - Part 18-31: Functional Evaluation of Insulation Systems - Test Procedures for Form-Wound Windings - Thermal Evaluation and Classification of Insulation Systems Used in Rotating Machines, IEC 60034-18-31; or
  • The Recommended Practice for Thermal Evaluation of Unsealed or Sealed Insulation Systems for AC Electric Machinery Employing Form-Wound Pre-Insulated Stator Coils for Machines Rated 15 000 V and Below, IEEE 1776.

Testing insulation materials and certification services

Working with us for all of your insulation testing needs makes the certification process easy and affordable. Our full-suite of services includes:

General purpose models

We offer in-house motorette assembly in addition to thermal-aging testing.

Sealed tube chemical compatibility testing

After completion of a full thermal-aging program, you may wish to add new (minor) components to an EIS. These components can include fastening tapes, tie cords, balancing compounds and other materials commonly used in mechanical applications.

Full thermal aging

Full thermal aging is designed to monitor degradation of the insulation system. A typical full thermal aging program lasts 12-18 months with many international standards also requiring testing for this duration.

Short-term thermal aging test for motors

Speed-to-market is key in the electrical motors industry, and the use of new insulating materials often determines your success. Our short-term thermal aging (STTA) test for motors, which certifies to the UL 1004-x series rotating electrical machines, is specifically designed to accelerate your time to market.

Defined life thermal aging

Our defined life thermal aging (DLTA) certification program is intended for insulation systems that are used in applications where the operational designed service life is 5,000 hours or less.

High-voltage electrical insulation systems

We offer high-voltage (HV) electrical insulation system evaluations that are specifically designed to address the performance of HV form-wound rotating machinery and HV power and distribution transformers.

Benefits of testing and certifying electrical insulation materials and systems

Thermal stress is the primary factor affecting the service life of insulating materials in electrical equipment. Our systemic and holistic approach to EIS certification increases confidence in the whole system, and therefore, provides equipment manufacturers with additional peace of mind that the EIS is safer for long-term use.

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Trust in your electrical insulation
systems and materials

Why UL Solutions for EIS testing and certification

We have a unique way of evaluating and certifying EIS. In addition to assessing insulation materials as individual components, we also evaluate the applicable system as a whole. This allows us to determine if components interact in unsafe ways or react chemically at certain maximum temperatures, which may cause product failure or other hazards to occur.

We are constantly expanding our EIS portfolio to better serve component manufacturers and original equipment manufacturers (OEMs). Having access to our full-suite of services, along with our technical team, allows you to easily keep pace with the new technological developments in your respective industry. That’s how we help you achieve what’s possible.

Download our resources

Performance Materials - Electrical Insulation Systems and Materials

2.12 MB

UL 1446 Compliance Options for Electrical Insulation Systems

2.07 MB

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