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Short-Term Thermal Aging Test for Motors

As a leader in science safety and testing, we’ve developed a new insulation system evaluation method to help get your “Rotating Electrical Machine” to market in less than two months.

A close-up image of a motor’s electrical wiring.


Speed to market is key in the electrical motors industry, which is why we’ve developed an alternate insulation system evaluation method to help you beat out the competition. Our Short-Term Thermal Aging (STTA) Test for Motors is specifically designed to accelerate certification time to the UL 1004-x Series Rotating Electrical Machines Standard and help get you to market in less than two months.

The test requirements are covered in UL 1004-1 Annex A and involve cycling the actual motor insulation through elevated temperatures and humidity exposures for 4 cycles totaling 1000 hours. Compliance is determined by an electric strength test on the motor insulation.


  • Reduced time to market due to an accelerated evaluation
  • Less expensive than the traditional UL 1446, the Standard for Systems of Insulating Materials – General, program
  • Reduced sample preparation costs and time due to actual motor testing

Why UL

We have a unique way of evaluating and certifying insulation systems. 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 insulations systems 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.

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Learn how to accelerate your time to market with UL’s 50-day test method: short-term thermal aging test for motors.

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