Ensure electrical insulation systems can take the heat by testing for compliance with UL 1446

Many electro-magnetic devices, including motors, transformers, generators, and solenoids, operate at high temperatures. Ensuring the durability of their electrical insulation system (EIS) under such extreme conditions plays a crucial role in safety, and also in reliable and efficient operations.

So, what makes the difference between a highly reliable and a poorly performing EIS? The answer lies in the electrical insulation materials (EIMs) that make up an EIS, and how they perform in combination with one another to withstand aging. Aging mechanisms may be influenced by mechanical or environmental, but particularly thermal stress. This can lead to temporary degradation or permanent damage to the EIS. Once this occurs, devices break down and even present a risk of fire or electric shock.

How well EIMs resist thermal aging depends on how well the individual materials respond with each other. Every EIS is unique in design and application, which can be daunting. When it comes to extreme temperatures, manufacturers can find guidance in testing that zeros in on and evaluates the thermal performance of EIMs and their interaction in the complete system.

UL 1446 - taking the heat off of manufacturers

End-product manufacturers profit from working with a partner who understands exactly the relation between EIMs performance and thermal aging. The UL 1446 “Systems of Insulating Materials” covers the guidelines and test methods for evaluating the thermal performance and chemical compatibility of insulating materials and their interaction as a whole under heat load and other stresses (mechanical, cold shock and moisture). Demonstrating compliance with this de-facto standard paves the way for manufacturers to meet the requirements for the applicable end-product standards.

Does my electrical end-product need all this?

Some end-product manufacturers may be uncertain if their electrical device or equipment really requires extensive test methods. As a general rule, if the EIS hot spot temperature is greater than 105°C, there’s a good chance thermal degradation may occur, and UL 1446 is therefore mandatory. 

A variety of options for UL certification of EIS

UL offers several options to demonstrate compliance to UL 1446. The three most common evaluations are:

• Full Thermal Aging Test: designed to monitor thermal degradation of a new EIS over time and is performed on non-functioning general-purpose models or on actual electro-technical device samples. 
• System Adoption Process: ideal for end-product manufacturers who don’t develop their own EIS but use an UL-certified EIS from a material supplier listed in UL’s iQ EIS database; quick and cost efficient.
• Sealed Tube Chemical Compatibility Test: for add-on, non-electrical insulating materials; addresses the compatibility of an insulating material with other materials in the same insulation system.

Other alternative compliance options offered by UL are: Defined Life Thermal Aging Test, High-Voltage EIS Full Thermal Aging Tests, and Short-Term Thermal Aging Test for Motors. These options cover a wide range of requirements that can govern end-product standards.

The best laid plans start with testing

Compliance options for electrical insulation systems (EIS) don’t need to be complicated or slow down the production of your electrical devices. On the contrary, they open the door to seamless production and accelerated acceptance of products on the market. Find out how you can get started with UL 1446 compliance.